8 Tight House Races to Watch on Election Night

— -- This year, Republicans are working to defend their 30-seat House majority -- the largest since 1928 -- from any down-ballot fallout from the presidential campaign. As results pour in on Election Night, here are some close races to watch:

Virginia 10: Keeping Distance From Donald Trump in Northern Virginia

Rep. Barbara Comstock, the freshman GOP congresswoman representing the D.C. suburbs, needs Trump backers to help her win re-election in northern Virginia. But she’ll also need the support of well-educated and affluent suburban women the GOP nominee has alienated. She's walked a fine line, mentioning the GOP nominee on the stump, but also calling on him to withdraw from the race after the release of a 2005 video of Trump making lewd comments about groping women. Real estate executive LuAnn Bennett, the Democratic candidate, and outside groups have flooded airwaves with ads linking Comstock to the GOP presidential nominee. ABC News Race Rating: Tossup

Florida 07: Top Republican Fights to Save Political Career

Rep. John Mica, the former chairman of the House Transportation Committee, faces the toughest re-election fight of his career. Redistricting has left his Orlando-area seat younger and more Democratic-leaning, making him vulnerable to Democrat Stephanie Murphy, a former Defense Department analyst and the daughter of Vietnamese refugees. A Mica loss on Election Night in Florida -- one of the first states where polls close -- could be a warning sign for House Republicans. ABC News Race Rating: Tossup

New York 24: GOP Workhorse Faces Former Senate Staffer

A freshman member of the House Homeland Security Committee, Rep. John Katko has been the most productive rank-and-file House Republican in the 114th Congress. According to legislative data compiled by CQ for ABC News, Katko has authored 14 measures passed through the chamber. His record could help insulate him from Colleen Deacon, a former aide to Sen. Kirsten Gillibrand, in the Syracuse area. ABC News Race Rating: Leans Republican

New Jersey 05: Controversial Comments Put Republican on Defense

Democrats have relentlessly targeted Rep. Scott Garrett for months after reports that he opposed supporting gay Republican candidates, giving former Bill Clinton speechwriter Josh Gottheimer an opportunity to swing the conservative northern New Jersey district. In the final stretch of the campaign, Democrats hope Trump’s slide with well-educated suburban voters has put Garrett’s seat within reach. ABC News Race Rating: Tossup

Florida 26: Former Congressman Takes On Early Trump Critic

Rep. Carlos Curbelo, a moderate Cuban-American Republican supportive of comprehensive immigration reform and bipartisan gun control, was one of the first members of Congress to condemn Trump's campaign. He could benefit from running down-ticket from Sen. Marco Rubio, who outperforms Trump with Hispanics in Florida, and faces a flawed challenger in Rep. Joe Garcia, his 2014 opponent who was caught making lewd comments about Hillary Clinton. ABC News Race Rating: Tossup

California 49: Obama Antagonist Strikes Bipartisan Tone

As the chairman of the House Oversight Committee, Rep. Darrell Issa was one of President Obama’s loudest critics on Capitol Hill -- and once suggested he was one of the most corrupt presidents in history. Locked in a race for his political life against former Marine Col. Doug Applegate, Issa is now hitting bipartisan notes. He’s sent mailers to constituents touting his work with Obama (Obama called the tactic “shameless” at a recent San Diego fundraiser), and even said he’d be willing to advise a President Hillary Clinton if she asked for his counsel. Democrats privately concede that picking off Issa is unlikely, but aren't ruling it out if Republicans stay home and independents turn to Applegate. ABC News Race Rating: Leans Republican

Colorado 06: Hispanic Voters Could Swing Denver Suburbs

Rep. Mike Coffman, who faces off against Democrat Morgan Carroll, a former Colorado Senate president, is no stranger to tight races. His increasingly diverse district in suburban Denver is among the most competitive every two years. He’s taught himself Spanish -- and continues to work with a tutor -- to connect with the large Hispanic community in his district. Coffman was one of the first Republicans to promise to “stand up” to Donald Trump in a campaign ad -- and now says he isn’t even sure if he’ll vote for a presidential candidate. ABC News Race Rating: Tossup

Florida 18: Republicans on Offense in South Florida

With Rep. Patrick Murphy running for Rubio’s spot in the Senate, his open House seat is one of the few Republicans hope to flip this year. They’re confident Republican Brian Mast -- an Army veteran who lost both legs in Afghanistan -- can take down Randy Perkins, a wealthy businessman who is self-funding his campaign.