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From the suburbs of Seattle to the union halls of New York, thousands of volunteers are contributing their sweat to help their candidates eke out a victory in the toughest, closest House races across the country.

More than the individual races are at stake — taking control of the House for the first time since 1994 is on the Democrats' minds, and while political observers suggest it's probably unlikely, narrowing the margin will give Democrats greater weight to put more of a squeeze on their GOP counterparts and President Bush.

"If Bush loses the House, then it will be a great blow and he would have to change the way he operates," suggested John Fortier, research fellow for the American Enterprise Institute (search).

On the flip side, if John Kerry wins, but faces at best an ambivalent Republican majority, he will surely have a hard row to hoe. If Democrats take over the House and Kerry wins, then the new president will have a much easier time pushing through his own initiatives.

"In terms of a changeover going on in the House, [the chances] are slim, even though there is such a narrow margin," said Fortier.

Currently, the House is comprised of 229 Republicans, 205 Democrats and one independent who votes with the Democrats.

Nathan Gonzales, political editor for the Rothenberg Political Report (search), said Democrats need to pick up at least 12 seats to achieve a takeover, a situation he finds "hard to argue" might happen.

Gonzales said out of the 435 seats up for grabs on Nov. 2, Rothenberg has put 42 in the competitive category. Of those, 25 are Republican seats, 15 are Democrat and two are incumbents running against each other.

"Republicans are on the defense more, but the burden of proof to win the House majority is with the Democrats," Gonzales said.

Only about a dozen or so out of those 42 competitive seats are considered real "toss ups," say election watchers, but they will make this Election Day a must-see for political junkies, as candidates, operatives and supporters bite their nails in these last weeks before the main event.

“The playing field is quite small — there aren’t many competitive seats — but the ones that are competitive can be quite close,” said Fortier.

Democrats may be able to make some gains, but many elections analysts predict that in the end, no side will win any landslide, and therefore, unless a change in the presidency comes, the House in January will continue to operate as it has been.

"I think it's a wash," said Fortier. "It's looking like the status quo."

Canvassing Washington, D.C., election-watchers, FOXNews.com has composed an analytical "cheat sheet" to monitor 16 "must-watch" House races. The selected races are in alphabetical order, rather than by any ranking of importance.

Arizona District 1: Paul Babbitt (D) v. Rep. Rick Renzi (R)

This race pits a first-term Republican congressman against the brother of former Clinton Interior Secretary and Arizona Gov. Bruce Babbitt in a district that has at least 34,000 more Democrats than Republicans.

"A recent poll showed [Renzi] ahead a little bit, "but I would say this is a race [Republicans] should be worried about," Fortier said.

Colorado District 3: John Salazar (D) v. Greg Walcher (R)

Salazar, a farmer, and Walcher, a state administrator, are competing for the seat left by retiring Republican Rep. Scott McInnis. The district leans Republican in terms of registration, but voters are not known as party loyalists.

"It’s a pretty hot race," Gonzales said. "And the state is on the fringe of being a presidential battleground state," he said, which could only benefit voter turnout on either end.

Georgia District 12: John Barrow (D) v. Rep. Max Burns (R)

Democrats say Burns won his first term in 2002 by a fluke, and they are putting up Athens-Clarke County Commissioner John Barrow to challenge him in this predominantly Democratic district.

"This is one that Democrats are putting on the top of their target list but Max continues to work hard and do all of the things he needs to be re-elected," said Carl Forti, spokesman for the National Republican Congressional Campaign.

Kentucky District 4: Nick Clooney (D) v. Geoff Davis (R)

Rep. Ken Lucas, the only Democrat in the state delegation, is retiring. Newsman and regional celebrity Clooney is Lucas’ recruit, but Davis, who lost to Lucas by a small margin two years ago, is giving him a fight in this predominantly Republican district.

"Clooney is probably going to have an advantage because of his name identification," said Michael Slider, who is running as an independent in the race. "But on the whole, I would say that Geoff Davis is the favorite because he’s a Republican."

Louisiana District 3: Damon Baldone (D) v. Charmaine Caccioppi (D) v. Charlie Melancon (D) v. Craig Romero (R) v. Billy Tauzin III (R)  

Louisiana District 7: Charles Boustany (R) v. Don Cravins (D) v. Willie Mount (D) v. Davis Thibodaux (R)

Two races are up for grabs in this state. Republican Rep. Billy Tauzin from the 3rd District and Democrat Chris John from the 7th District are both retiring. Louisiana’s election system calls for a run-off, rather than a separate primary, thus the numerous players vying for the prize. According to the Cook Political Report, Tauzin’s son Billy Tauzin III is leading the pack, followed by Melancon, in the 3rd; a July poll found the two Democrats leading the race in the 7th.

New Mexico District 1: Richard Romero (D) v. Rep. Heather Wilson (R) 

Wilson is serving her fourth term in this predominantly Democratic district and her tested leadership gives her the edge, say analysts. But Romero, the state Senate president and 2002 candidate, is within reach, according to the most recent polling.

"It’s a competitive, competitive district," said Fortier.

New York District 27: Brian Higgins (D) v. Nancy Naples (R)

Republican Rep. Jack Quinn is retiring after six terms in this predominantly Democratic district. Republicans say Naples can beat the system and win. State Assemblyman Higgins said Democratic voters in the district won’t let that happen.

"By voter registration and voting performance, it is a Democratic seat, but Republicans have a great candidate in Nancy Naples," said Gonzales. "This is a seat Democrats have to win."

Pennsylvania District 13: Melissa Brown (R) v. Allyson Schwartz (D) 

Democratic Rep. Joe Hoeffel is leaving this suburban Philadelphia seat to run for Senate. Schwartz is a state senator, Brown is an ophthalmologist and lost to Hoeffel in 2002 by 4 percent. The race appears close, and it has become expensive.

"It’s a battleground state and one of the biggest swing districts in the country," said Emily’s List (search) Political Director Karen White, who called this race one of her group’s top targets.

Utah District 2: Rep. Jim Matheson (D) v. John Swallow (R)

Matheson is in his second term in a district that is a predominantly Republican conservative district. Swallow, the 2002 candidate, is taking a second swipe, and he’s getting help from groups like the formidable Club for Growth (search).

"There have been polls that show [Matheson] significantly ahead," said Fortier. "But he has always had tough races."

Washington District 8: Dave Reichert (R) v. Dave Ross (D)

Six-term Republican Rep. Jennifer Dunn is retiring from this competitive suburban Seattle district. Reichert is best known as the county sheriff who captured the Green River Killer. Ross is the well-known host of a talk radio show.

"Both guys are similar in that they don’t have a long history in partisan politics, but they have name ID for different reasons," said Gonzales.

Texas District 1: Louis Gohmert (R) v. Rep. Max Sandlin (D)

Texas District 2: Rep. Nick Lampson (D) v. Ted Poe (R)

Texas District 17: Rep. Chet Edwards (D) v. Arlene Wohlgemuth (R)

Texas District 19: Rep. Randy Neugebauer (R) v. Rep. Charlie Stenholm (D)

Texas District 32: Rep. Martin Frost (D) v. Rep. Pete Sessions (R) 

Thanks to GOP redistricting, incumbent Democrats are on the run in Texas this year. Some are running against Republican challengers in completely new districts, others are running against Republican incumbents. Analysts say Republicans are guaranteed to pick up some new seats on Election Day. The above are the most competitive.

"In the House [races], you are talking about two worlds — Texas and everywhere else," said Fortier. "The big picture is the Republicans are going to pick up seats in Texas, and I think the Democrats have a better chance of picking up seats outside of Texas."