By Chris Cillizza

In the battle for control of the House environment isnt everything but its darn close to being the only thing. Heading into the summer the political environment had been neutral to slightly positive for Democrats. But it turned in a meaningful way as Labor Day approached and anger over the growth of government under President Obama emboldened Republicans. The signs of this environmental change were everywhere.
House races -- with less-well-known candidates and less money flowing through them than Senate contests -- tend to be heavily influenced by which way the national winds are blowing.
The generic ballot edge that Democrats had maintained for the better part of the last two election cycles disappeared; in the latest NBC-Wall Street Journal poll 43 percent of respondents said they preferred a Democratic-controlled Congress while 40 percent said they would like to see Republicans running things on Capitol Hill. (As recently as April Democrats had a nine-point lead on that question.)
Recruitment also began to pick up for Republicans with top-tier candidates who might have taken a pass in years past stepping up to run -- for example state Sen. Bob Gibbs in Ohios 18th District and former U.S. attorney Tim Griffin in Arkansass 2nd.
Those developments led some of the nations leading political prognosticators such as Charlie Cook and Larry Sabato to predict that Democrats were headed for a world of hurt in 2010 with the loss of 20 or more House seats not out of the question. (A third respected political analyst -- Stu Rothenberg -- was slightly more circumspect about just how bad the environment is for House Democrats.)

Heres a look at the five seats most likely to change hands after next years elections:
5. Illinois 10th District (Republican-controlled): This North Shore district has been held relatively easily by Rep. Mark Kirk (R) for much of the past decade but those election results belie the strong Democratic underpinnings of an electorate that gave Obama 61 percent of the vote in 2008. With Kirk now running for the Senate this is a major target for Democrats. Dan Seals who ran against Kirk in 2006 and 2008 is hoping the third times the charm while state Rep. Julie Hamos (D) is also a serious contender. State Rep. Elizabeth Coulson and businessman Dick Green are the leading candidates on the Republican side.
4. New Mexicos 2nd (Democratic-controlled): Not only did Rep. Harry Teague (D) inexplicably vote in favor of the Obama administrations cap-and-trade energy bill earlier this year (his southern New Mexico district is filled with oil and gas companies) but he has also drawn his toughest possible opponent -- former congressman Steve Pearce (R) -- as he prepares to seek a second term in 2010. Not good.
3. New Yorks 23rd (R): While Republicans outnumber Democrats by registration in this North Country seat the GOP is in the midst of tearing itself apart as Conservative Party candidate Doug Hoffman (with a major assist from the Club for Growth) savages state Assemblywoman Dede Scozzafava (R) as insufficiently conservative. Meanwhile businessman Bill Owens (D) is up with ads touting his military background and r?sum? as a job creator in an area that is in desperate economic straits.
2. Louisianas 3rd (D): Senate Democrats gain is House Democrats loss when it comes to Rep. Charlie Melancon (D). Melancons decision to take on Sen. David Vitter (R) in 2010 leaves open his seat in a southeastern Louisiana district where Obama won just 37 percent of the vote last November. Natural Resources Secretary Scott Angelle is seen as the 800-pound gorilla in the race and if Democrats can get him to run under their banner they could have a shot at holding the seat. (Angelle is considering the race but hasnt announced whether he would run as a Democrat or a Republican.) No matter what happens this is a very tough hold for Democrats.
1. Louisianas 2nd (R): Rep. Joseph Cao (R) isnt coming back to Congress in a New Orleans area district that gave Obama 74 percent of the vote last year. The real fight is for the Democratic nomination.