Republican Leader Mitch McConnell is the most unpopular Senator in the country, according to a new survey conducted by Public Policy Polling released Tuesday.The poll shows that among Kentucky voters, McConnell has just a 37 percent approval rating along with a 55 percent disapproval and has only one-third of independents. But the GOP leaders is still ahead of all Democratic threats in 2014, including actress Ashley Judd, Secretary of State Alison Lundergan Crimes and Louisville Mayor Greg Fischer.From PPP: The reason McConnell does decently well in the head to head match ups despite his poor approval numbers is that even though a lot of Republicans dislike him, most of them would still vote for him in a general election before they would support a Democrat. This is the same phenomenon we saw in Florida and Pennsylvania this year where Bill Nelson and Bob Casey won by solid margins despite middling approval numbers because Democrats that weren't thrilled with them still voted for them. And although independents don't like McConnell they don't like most of the Democrats either, and they support McConnell in every match up we tested.Observers highlight that while Kentucky went solidly for Republicans in the 2012 campaign, McConnell is vulnerable and up by only four points over Judd and Grimes, who are considered to be the top contenders to take him on in two years.Fischer—who ran unsuccessfully for the Senate Democratic nomination in 2008—trails McConnell by just five points."Kentucky is a tough state for Democrats," Public Policy Polling President Dean Debnam said in a news release. "But given how unpopular McConnell is and how few opportunities there are for them to play offense in 2014, this should be one of the most hotly contested races in the country.”What's also telling is the level of dissatisfaction amongst McConnell's base despite his efforts to court the Tea Party.According to PPP, 35 percent of Republican primary voters said they want a candidate more conservative than McConnell. And while 59 percent of Republicans approve of McConnell's job performance, that is below 70 to 80 percent approval that PPP says most incumbent Senators have within their own party.In response, McConnell's re-election campaign attacked PPP and highlighted an article questioning the methodology of using robo-call polls to measure a lawmaker's approval. However, PPP responded by showing that the article's author was wrong about Kentucky's 2010 Senate race when the polling group had now-Sen. Rand Paul defeating former Secretary of State Trey Grayson.The Team Mitch Twitter account also cited a poll by The Courier-Journal that showed McConnell with a 51 percent approval rating amongst voters.