Sensing McConnell could be defeated, challengers try to unseat veteran Republican leader Emboldened by the far-ranging criticism of Kentucky Sen. Mitch McConnell as he tries to lead Republicans in a Democrat-controlled Senate, candidates from both parties are challenging the Senate minority leader's 2014 reelection bid. Among the most recent to join the race are Republican candidate Matt Bevin, a Kentucky businessman and political newcomer, and Democratic challenger Alison Lundergan Grimes, Kentucky's secretary of state. Much of the criticism about McConnell comes from the extremes of both parties. The argument that McConnell continuously tries to maneuver and block Obama and the Senate majority's legislative agenda comes mostly from the more liberal faction of the Democratic Party, who also point to his 2010 comment that making President Obama a "one-term president" should be Republicans" top priority. However, the conservative wing of his Republican Party has also been critical, saying McConnell has cast aside their core values in compromising with Democrats on such key issues as immigration reform, confirming Obama appointees and raising the federal debt limit. Such concerns have resulted in Bevin endorsements from conservative groups including the Madison Project and the United Kentucky Tea Party, a coalition of 14 like-mined organizations. "For years, Sen. McConnell has been undermining conservatives in the Senate, even as he evinces the image of a conservative warrior to his constituents," the Madison Project said in endorsing Bevin. The endorsement by the fundraising group is expected to give Bevin access to donors across the country, which he will need considering McConnell's $10 million war chest that he uses to help club essentially anybody who even hints at a challenge. His campaign, for example, posted an attack ad last week within hours of Bevin officially declaring his candidacy that accuses him of being a tax deadbeat and taking $200,000 in taxpayer bailout money for his Connecticut business. Bevin dismissed the allegations, telling Fox News they are a "smoke screen" because McConnell has no record on which to stand. Roughly six months earlier, the McConnell campaign showed its hardball tactics in a secretly recorded tape about plans for actress Ashley Judd, whom Democrats were floating as a challenger. "I assume most of you have played the game Whac-A-Mole?" the 71-year-old McConnell is heard saying. This is the Whac-A-Mole period of the campaign... . When anybody sticks their head up, do them out. Staffers on the tape also seem to discuss bring up Judd's history of mental-health problems, and they purportedly worked with the FBI on finding the taping culprits. As the 2014 election season unofficially starts after Labor Day, McConnell has a double-digit lead over Bevin and a slight lead over Grimes, though most political analysts think he will win a sixth term. He is running in a Republican-leaning state in which Obama won just 38.5 percent of the vote last year, and GOP nominees have won the state's past six U.S. Senate contests. In addition, McConnell has his own Tea Party support going into the primary -- the backing of the national group Tea Party Nation and Kentucky GOP Sen. Rand Paul, elected as part of the 2010 Tea Party wave. And he has hired as campaign manager Jesse Benton, a veteran Paul-family political adviser. Even Bevin, during his campaign announcement, acknowledged the long odds in saying: "Never in the history of American politics has a party leader in the United States Senate been defeated in the primary." Should McConnell win the primary, he will continue to try to link Grimes to Obama, while Grimes tries to portray him as major factor in the so-called Capitol Hill gridlock. On Tuesday, during Grimes" first official campaign stop, she suggested McConnell embodies Washington's "disease of dysfunction." And she made clear she was ready for his rough-and-tumble campaign style. "I have a message for you, Sen. McConnell," Grimes told the crowd of supporters. I don't scare easy, and neither does the rest of Kentucky. Stuart Rothenberg, of the non-partisan Rothenberg Political Report, appeared earlier this month to give the final edge to McConnell, though he accepts Democrats" argument that McConnell seems more vulnerable now than he has in the past. "He may well be," Rothenberg said. But that doesn't mean that Democrats can beat him next year. However, he also warned: "This is a race worth watching, and Republicans ought not dismiss the challenge."