Harshest Attacks in the GOP Slugfest 2012 Campaign: The Harshest and Sharpest Attacks Of GOP Race If You're in the Market for an Insult, the GOP Race Is Ripe With Inspiration If you're in the market for an insult, the GOP race is ripe with inspiration. From veiled swipes at a primary opponent's policies to direct attacks on a general election rival's character, this campaign has been one of the most vitriolic in history. A full 50 percent of all the ads run so far in this campaign season have been negative, a huge jump from the 8 percent of ads that were negative during the 2008 election. And while much of the negativity on the airwaves is coming from well-funded, unlimited donation-collecting super PACs, the candidates and their surrogates have done their fair share of bad-mouthing. Here's a look at some of the mud being slung in this contentious race to the White House. Gingrich v. Obama Most Dangerous President While Republican infighting is at record highs, some of the harshest candidate criticism has been reserved for the man on the other side of the aisle: President Obama. The political fury of Newt Gingrich landed squarely on the president's foreign policy platform Monday when the GOP candidate dubbed Obama the "most dangerous president in modern American history." At a campaign stop in Tulsa, Okla., Monday, Gingrich said defeating Obama was "in fact, a duty of national security." "Because the fact is, he is incapable of defending the United States," the former House Speaker said. Gingrich noted that in this "dangerous" world, Obama is failing to deal with international threats. "The president wants to unilaterally weaken the United States, he wants to cut the aide to Israel for its anti-ballistic missile defense, he refuses to take Iran seriously," Gingrich said. Gingrich has said the United States should take whatever steps are necessary to prevent Iran from obtaining a nuclear weapon, but emphasizes that covert operations to assassinate the country's nuclear scientists should come first. Obama, on the other hand, has implemented stiff sanctions against the country. His administration is strongly urging Israel not to attack Iran's nuclear facilities, as it is threatening to, but maintains that Obama is a strong supporter of Israel. GOP Senator v. Romney Too Damaged As his home state, Michigan could be a make or break election for Mitt Romney in the primary next week. As one GOP senator told ABC's Jonathan Karl, "if Romney cannot win Michigan, we need a new candidate." The senator, who requested anonymity, said Republicans would "get killed" in the general election if Romney became the nominee but could not even win in the state in which he grew up. "He'd be too damaged if he can't even win in Michigan, where his family is from, where he grew up," said the prominent GOP senator, who has yet to endorse a candidate. While there have been few recent polls on the state of the Michigan race, Santorum has eclipsed Romney in the most recent national polls. As of Monday, Santorum stood 10 points higher than the Michigan native in the nationwide Gallup daily tracking poll. Santorum v. Obama Phony Theology Rick Santorum took his criticism of the president to the next level Saturday when he accused Obama of operating under a "phony theology." It's not about your job," Santorum said of the president's agenda at a Tea Party rally in Columbus, Ohio. It's about some phony ideal, some phony theology. While Santorum has since insisted that he was not questioning Obama's Christian faith, Obama's deputy press secretary Ben LaBolt said his comments were the "latest low in a Republican primary campaign that has been fueled by distortions, ugliness, searing pessimism and negativity." Robert Gibbs v. Santorum Well Over the Line Question his policies, criticize his decisions, but don't mess with President Obama's religion, or you'll have to answer to former Obama press secretary Robert Gibbs. Gibbs blasted Santorum Sunday for being "well over the line" for saying the president operated under a "phony ideology." "It's wrong, it's destructive and it makes it virtually impossible to solve the problems we face together as Americans," Gibbs said Sunday on ABC's "This Week." Gibbs said the GOP primary has been a "race to the bottom" with candidates opting for character attacks rather than sticking to policy decisions. Santorum v. Romney Does the Word Hypocrisy Come to Mind? At a time in U.S. politics when "bailout" is a four-letter word and "earmark" is nearly a bleep-able offense, Santorum charged Romney with having "heroically bailed out" the Salt Lake City Olympics by securing an "earmark" from Congress. "He heroically bailed out the Salt Lake City Olympic Games by heroically going to Congress and asking them for tens of millions of dollars to bail out the Salt Lake games â in an earmark, in an earmark for the Salt Lake Olympic games," Santorum said while campaigning in Ohio on Saturday. Romney often touts his tenure at the helm of the 2002 Winter Olympics as an example of his business experience. Romney claims to have saved the games after a bribery scandal, but has come under fire for requesting federal money to prop up the troubled Olympics. Romney's Olympic "bailout," as Santorum calls it, is not the only insult the former Pennsylvania senator was slinging Saturday. "Now Governor Romney is suggesting, 'Oh, Rick Santorum earmarked,' as he requested almost half a billion dollars in earmarks as governor of Massachusetts to his federal congressmen and senators," Santorum said. Romney v. Santorum 'You Can't Vote for Him' Romney left the sugar-coating at home during a campaign speech in Boise, Idaho, Friday. The former Massachusetts governor told the crowd straight up that they "can't vote for Rick Santorum." "If you want a fiscal conservative you can't vote for Rick Santorum because he's not, he's not a deficit hawk, he says he's not a deficit hawk," Romney said. Romney rarely mentions Santorum by name on the campaign trail, but after Ohio Attorney General Mike DeWire switched his support from the Romney camp to the Santorum team, Romney was riled up and on the attack. "Senator Santorum is getting his moment in the spotlight now, which is a good thing," Romney said. I hope people take a very close look at his record, because he was in Congress for about 20 years and during that time the size of the federal government doubled during his time in office. "And by the way," Romney added, "he voted to raise the debt ceiling five different times without compensating cuts. Pet Lovers v. Romney Mean to Dogs It might sound like a trite pull on the emotional heart strings, but the accusation that Romney is "mean to dogs" is a charge that is proving to be immortal. The story of Romney strapping family dog Seamus' kennel, with the dog inside, to the top of his station wagon during a 12-hour drive has come back to haunt the presidential candidate more than 20 years after the fact. The tale has now spawned the anti-Romney group "Dogs Against Romney," which protested outside the Westminster dog show in New York City this week "to ensure pet lovers are aware that Mitt Romney is mean to dogs."