Donald Trump supporter Newt Gingrich on Sunday sharply criticized the presumptive GOP presidential nominee for his racially-sensitive remarks about the judge presiding over the Trump University civil fraud case. 
 
 “It was one of the worst mistakes Trump has made. Inexcusable,” the former GOP House speaker, who has become one of Trump’s closest advisers, told “Fox News Sunday.” 
 
 Trump has argued that American-born District Judge Gonzalo Curiel, whose parents are from Mexico, is biased against him, considering Trump’s vow to build a wall along the southern U.S. border to keep out Mexicans. 
 
 “He’s Mexican,” Trump told CNN on Friday. “We’re building a wall between here and Mexico.” 
 
 Gingrich, whose is considered a potential Trump running-mate, also called the comment a “mistake” but stopped short of calling it racist. 
 
 “That judge is not a Mexican. He’s an American,” he said. “I hope it was sloppiness.” 
 
 Still, Gingrich continued to laud Trump, particularly for the first-time candidate's defeat of 16 other major GOP candidates to win the party nomination. 
 
 “I’m amazed at his speed, how fast he learns,” Gingrich said. “He’s a remarkable leader. We have a very good relationship.” 
 
 However, he argued the billionaire businessman is at a “turning point” in which he must become more disciplined and take more of his campaign advisers’ advice if he wants to defeat Democratic presidential front-runner Hillary Clinton in the general election. 
 
 “Compared to Hillary Clinton, I’d support Donald Trump all year,” Gingrich said. “She’s a much more flawed person.” 
 
 Trump University is the target of two lawsuits in San Diego and one in New York that accuse the business of fleecing students with unfulfilled promises to teach secrets of success in real estate. 
 
 Trump has maintained that customers were overwhelmingly satisfied. His legal team has not sought to have Curiel removed. 
 
 Trump on Sunday again defended his comments about the judge and dismissed Clinton’s assertion that his remarks are “racist.” 
 
 “I have been treated very unfairly by this judge,” Trump told CNN’s “State of the Union.” 
 
 In an extended back-and-forth exchange with host Jake Tapper, Trump acknowledged that Judge Curiel is indeed from Indiana but argued that he’s “very proud” of his Mexican heritage, to the extent he is a member of a “very pro-Mexico society.” 
 
 “I’m building a wall. I’m trying to keep business out of Mexico,” said Trump, suggesting the situation has created a conflict of interest for the judge. 
 
 He also suggested Clinton should be “put in jail” for using a private email server while secretary of state and called her a “stiff.” 
 
 Trump, who after a series of terror attack also called for a temporary ban on Muslims entering the United States, told CBS' "Face the Nation" that "it’s possible" that a Muslim judge would treat him unfairly. 
 
 Clinton on Sunday was again critical of Trump’s comments about the judge, which she called inaccurate and “very vicious.” 
 
 "Judge Curiel is as American as I am and certainly as American as Donald Trump is,” Clinton said on ABC’s “This Week.” 
 
 She also suggested that the attacks were “typical” of Trump’s strategy of trying to “divert attention” from his problems, in this case “very serious fraud charges” against the real estate school. 
 
 “Trump's continuing ethnic slurs and rants against everyone, including a distinguished federal judge, I think makes my point rather conclusively,” Clinton said. 
 
 Also on Sunday, a pair of powerful Senate Republicans warned Trump to drop his attacks on the judge. 
 
 "We're all behind him now," Senate Majority Leader Mitch McConnell said on NBC's "Meet the Press," adding that it's time for unifying the party, not "settling scores and grudges." 
 
 "I hope he'll change his direction," the Kentucky Republican also said. 
 
 Tennessee Sen. Bob Corker, chairman of the Senate Foreign Relations Committee, told ABC: "I don't condone the comments." 
 
 Their remarks solidify the line GOP leaders have drawn in recent days between themselves and Trump, with whom they've made a fragile peace over their sense that almost anyone would be a better president than Clinton. 
 
 The most-recent GOP pushback against Trump comes two days before presidential primaries in California, home to more Latinos than whites. 
 
 On Thursday, House Speaker Paul Ryan tepidly endorsed Trump -- but 24 hours later disavowed the billionaire's remarks about Curiel. 
 
 
 
 The Associated Press contributed to this report. ||||| Trump's comments come hours after he expressed confidence that he would win the case regardless of Curiel's alleged bias. | Getty Trump escalates attack on 'Mexican' judge 
 
 Donald Trump escalated his attacks on the federal judge presiding over a civil fraud lawsuit against Trump University on Thursday, questioning his impartiality in handling the case because his Mexican heritage is "an inherent conflict of interest." 
 
 Less than six hours after securing the endorsement of House Speaker Paul Ryan, the presumptive Republican nominee said that U.S. District Judge Gonzalo Curiel had “an absolute conflict” due to his ethnic background, adding, “I’m building a wall. It’s an inherent conflict of interest,” according to a interview in The Wall Street Journal. 
 
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 Curiel was born in East Chicago, Indiana, to Mexican parents. He spent years prosecuting drug traffickers coming across the U.S.-Mexico border as a top official in the Justice Department's South District of California, and was later appointed to the federal bench by President Barack Obama. 
 
 Trump's comments come hours after he expressed confidence that he would win the case regardless of Curiel's alleged bias. 
 
 "Even though I have a very biased and unfair judge in the Trump U civil case in San Diego, I have thousands of great reviews & will win case!," he wrote earlier on Thursday. "After the litigation is disposed of and the case won, I have instructed my execs to open Trump U(?), so much interest in it! I will be pres." 
 
 It's not the first time Trump has attacked Curiel. At a rally on Friday in San Diego, he called him a "hater" during a 12-minute diatribe about the Trump University case and mentioned the judge's Mexican background, though he called it "great" and "fine." 
 
 His campaign has likewise gone after Curiel on ethnic grounds — though it apparently confused one Hispanic group with another. 
 
 "I think what's really interesting about this particular judge -- as Mr. Trump refers to him as a 'Trump hater' -- is he even mentions on his judicial questionnaire that he was a La Raza Lawyers Association member," Trump spokeswoman Katrina Pierson said on CNN earlier this week. "This is an organization that has been out there organizing anti-Trump protesters with the Mexican flags -- they are pushing it. The signs have been very apparent. And so Mr. Trump is just stating the obvious." 
 
 Pierson seems to have mixed up the La Raza Lawyers Association — an apolitical, professional group for Latino lawyers and judges — with the National Council of La Raza, a left-leaning Hispanic activist group headquartered in Washington, D.C. 
 
 Trump also leveled a new complaint against Curiel on Thursday: that he was friendly with one of the plaintiffs' lawyers in the Trump University case, a former colleague. 
 
 The lawyer, Jason Forge, denied that. 
 
 “Neither Judge Curiel’s ethnicity nor the fact that we crossed paths as prosecutors in the U.S. Attorney’s Office well over a decade ago is to blame,” Forge told the paper. 
 
 Curiel has yet to comment on Trump's accusations. 
 
 Later on Thursday night, an angry Megyn Kelly berated Trump supporter Bill Bennett about the real estate mogul's comments on her Fox News show. 
 
 “First of all, people are saying that this judge is a member of La Raza, the group that’s been protesting Donald Trump. He isn’t,” Kelly said. “He’s a member of a Hispanic lawyers' association that has no partisan stripes whatsoever. They support Hispanic lawyers and judges.” 
 
 Kelly, a former lawyer, pressed on. 
 
 “He has no conflict of interest, Bill,” she said. “Now Donald Trump is saying the judge needs to be investigated, someone should look into him just because he’s ruled against Donald Trump in his litigation repeatedly. That doesn’t make you biased. It just doesn’t.” 
 
 Kelly also speculated that Curiel is being harassed as a result of Trump’s attacks. 
 
 “When he does this, I guarantee you right now that this judge is getting threats and vitriol and who knows what else,” she said. ||||| FILE - In this March 16, 2016 file photo, Sen. Susan Collins, R-Maine, speaks with reporters on Capitol Hill in Washington. Collins is the latest Republican to reject GOP presidential candidate Donald... (Associated Press) 
 
 FILE - In this March 16, 2016 file photo, Sen. Susan Collins, R-Maine, speaks with reporters on Capitol Hill in Washington. Collins is the latest Republican to reject GOP presidential candidate Donald Trump’s comments about the ethnic background of an American federal judge. Trump is insisting that... (Associated Press) 
 
 WASHINGTON (AP) — Republicans roundly scolded their own presidential candidate Monday, demanding Donald Trump apologize for — and just stop — talking about the ethnic background and impartiality of the American judge overseeing a lawsuit against Trump University. 
 
 Leading the roll call were two former rivals for the Republican presidential nomination. 
 
 Ohio Gov. John Kasich tweeted that Trump's offensive against the impartiality of U.S. District Judge Gonzalo Curiel "is flat-out wrong." 
 
 Trump, Kasich wrote, should "apologize to Judge Curiel & try to unite this country." 
 
 Chimed in Florida Sen. Marco Rubio, "It's wrong and I hope he stops." 
 
 Other prominent Republicans piled on, drawing a solid line between themselves and the billionaire candidate with whom they've developed a fragile peace. But that detente comes with caveats — chief of which is the understanding that Trump, nomination nearly in hand, will now focus on uniting the fractured GOP. 
 
 Trump, too, showed some deference for the truce, declining to immediately hit back at the Republican lawmakers who have demanded he move on. 
 
 But no mea culpa seemed forthcoming from the billionaire candidate. Trump insisted earlier Monday that his criticism of Curiel came in defense against relentless questions from reporters and others about lawsuits against Trump University. Trump said Curiel can't be impartial in the suits because the jurist's parents were born in Mexico and Trump wants to build a wall along the border. Last week, he denied on CNN that his remarks are racist. 
 
 "Public Service Announcement: Saying someone can't do a specific job because of his or her race is the literal definition of 'racism,'" tweeted Sen. Ben Sasse, R-Neb., a longtime Trump critic. 
 
 Curiel is a former federal prosecutor who was born in Indiana to parents who came from Mexico in the 1920s. He has not responded to Trump's attack, and Trump's legal team has not sought his removal from the case. Judges generally are thought to have conflicts of interest only in more specific situations, such as a financial interest in the outcome of the case. 
 
 Trump University is the target of two lawsuits — in San Diego and New York — which accuse the business of fleecing students with unfulfilled promises to teach them secrets of success in real estate. Trump has maintained that customers were overwhelmingly satisfied. Curiel is presiding over the suits in California. 
 
 "All I'm trying to do is figure out why I'm being treated so unfairly by a judge," Trump said Monday on Fox News Channel. 
 
 The Republican establishment responded in rare unison: Just stop. 
 
 "He needs to stop saying it. That man is an American — born in the United States," Rubio, son of Cuban immigrants, told Orlando television station WFTV. "I don't think it reflects well on the Republican Party. I don't think it reflects well on us as a nation." 
 
 Added Republican Sen. Susan Collins of Maine: "Donald Trump's comments on the ethnic heritage and religion of judges are absolutely unacceptable. His statement that Judge Curiel could not rule fairly because of his Mexican heritage does not represent our American values." 
 
 And from the House side, Oversight and Government Reform Comimttee Chairman Jason Chaffetz urged Trump to "move on." 
 
 "Why doesn't he just say, 'Look, it's up to the attorneys' ... and leave it at that?" Chaffetz, R-Utah, said on Fox News Channel. 
 
 The cascade of condemnation began on the Sunday talk shows, when a trio of prominent Republicans firmly rejected Trump's focus on Curiel and urged him to make good on his promise to unite the fractured Republican Party. Senate Majority Leader Mitch McConnell said he "couldn't disagree more" with Trump's statements about Curiel's impartiality, adding that "we're all behind him now" — an implicit warning that such unity might not be the case for long. Senate Foreign Relations Committee Chairman Bob Corker said he doesn't condone Trump's statements about Curiel, then complained that his interview was supposed to be about foreign policy. 
 
 And former House speaker Newt Gingrich pointedly suggested that Trump start acting like "a potential leader of the United States." 
 
 Trump already has rejected calls for him to adjust his approach. 
 
 "I'm not changing," he said Tuesday at a fiery news conference at Trump Tower. 
 
 On Sunday, Trump doubled down on the idea. Asked on CBS whether a Muslim judge would be unfair given Trump's plan to ban Muslims from entering the U.S., Trump responded: "Yeah. That would be possible, absolutely." 
 
 That puts Trump in significant conflict with the Republicans he hopes to lead — including many of the ones who have opted to support him. 
 
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 Follow Laurie Kellman on Twitter at http://www.twitter.com/APLaurieKellman
– Donald Trump's claim that a US-born judge is a Mexican with a conflict of interest is "inexcusable" and "one of the worst mistakes Trump has made," according to Newt Gingrich, a Trump ally so staunch he has been talked about as a VP pick. "That judge is not a Mexican. He's an American," Gingrich tells Fox News. "I hope it was sloppiness." He adds: "If a liberal were to attack Justice Clarence Thomas on the grounds that he's black, we would all go crazy." But Gingrich stresses that he's still impressed by Trump, whom he considers a far better candidate than the "much more flawed" Hillary Clinton. "I'm amazed at his speed, how fast he learns," Gingrich says. "He's a remarkable leader. We have a very good relationship." He says Trump is now at a "turning point" where he needs to run a more disciplined campaign. Gingrich isn't the only Republican who has taken exception to Trump's remarks on Judge Gonzalo Curiel, who is overseeing two fraud cases against Trump University, and to Trump's suggestion Sunday that he would also consider a Muslim judge biased. "His comments are offensive and wrong and he should retract them," New Hampshire Sen. Kelly Ayotte tells the Washington Post. Paul Ryan and Mitch McConnell have also criticized the remarks. On ABC News' This Week, Clinton denounced the remarks as a "typical Trumpism" and an attempt to deflect attention from "very serious fraud charges" by attacking a distinguished federal judge. "Judge Curiel is as American as I am and certainly as American as Donald Trump is," she said.