In a sign of just how tough the midterm environment is turning for Democrats in the final stretch of the 2010 campaign, a new poll once again shows Rep. Walt Minnick (D-Idaho) fighting for survival in a district where it appeared the conservative Democrat would defy the odds this fall. 

After holding a double-digit lead in some public polls over his GOP opponent, state Rep. Raul Labrador, the latest numbers from Mason Dixon show the race in a dead heat. Minnick is up by just three points in the latest poll, despite enjoying a 10-point lead last month. 

Given the nature of his district, Minnick could never be considered safe regardless of his voting record, which is one of the most conservative in the nation for a House Democrat. Idaho's 1st district is overwhelmingly Republican. Sen. John McCainJohn Sidney McCainListen, learn and lead: Congressional newcomers should leave the extremist tactics at home Overnight Defense: Trump unveils new missile defense plan | Dems express alarm | Shutdown hits Day 27 | Trump cancels Pelosi foreign trip | Senators offer bill to prevent NATO withdrawal Bipartisan senators reintroduce bill to prevent Trump from withdrawing from NATO MORE (R-Ariz.) won 62 percent of the vote here in 2008.  

Minnick began the cycle as a top target of the National Republican Congressional Committee, but the committee's chosen candidate ended up losing in the GOP primary.

After Labrador defeated highly touted GOP recruit Vaughn Ward this past spring, Minnick's road to reelection became a bit easier. And throughout most of the summer and fall, Labrador has underperformed as both a fundraiser and candidate. 

Just two months ago, Minnick appeared safe despite the overwhelming GOP edge in the district. 

Like most of his fellow endangered Dems, Minnick has run from House Speaker Nancy Pelosi (D-Calif.), not committing to backing her again for Speaker should Democrats keep their majority in the House. 

The Democrat also voted against just about every major legislative priority for the House Democratic leadership during his first term, casting votes against healthcare, cap-and-trade, the stimulus and the Disclose Act. And Minnick has the backing of the U.S. Chamber of Commerce.  

"I campaign by myself, on my record," Minnick said in an interview with The New York Times this week. 

But the ground has shifted over the past two weeks. The Tea Party Express, which once backed Minnick, announced its backing of his Republican challenger last Friday. 

Minnick rebuffed the group's backing in July, following a controversy over a racially charged blog post written by former Tea Party Express Chairman Mark Williams.  

Now, after re-evaluating Minnick's positions, the group said it decided the Democrat has bowed to pressure from the Democratic leadership. 

"During the primary election campaign the Tea Party Express had endorsed Congressman Minnick for reelection in light of his independence in standing up to significant items in President Obama's agenda," Tea Party Express spokesman Levi Russell said in a statement Friday. "Since then, Congressman Minnick has engaged in a pattern of behavior which shows he is more responsive to the Democrat Party's establishment than he is the voters of Idaho."   

Minnick also faced an ad funded by the Super PAC for America, which falsely claimed the Democrat voted in favor of the stimulus. The PAC has since changed the ad, removing the reference to Minnick's vote on the stimulus.  

Illegal immigration has also become a major issue in the contest, too, with Minnick taking criticism from his Hispanic opponent for running ads Labrador says hint at the Republican's ethnic background. 

Now Republicans are once again hopeful that Minnick might end up a victim of the expected GOP wave next week in what would be a win for Republicans even in the face of a superior campaign waged by the Democrat.

-Updated at 10:05 p.m.