Childers, a former longtime local official who represents northern Mississippi, was first elected in a special election last May and re-elected in November by an even wider margin. His conservative views on social issues and other matters enable to do this in a strongly right-leaning district, where Republican Rep. Roger Wicker won seven House terms before he accepted an appointment to the U.S. Senate that created the vacancy filled by Childers. A Democrat cannot be considered completely safe for re-election on this turf, but Childers’ strong showings in two elections six months apart last year could be daunting to potential challengers.

• Bill Foster , Illinois’ 14th District (elected to 1st full term with 58 percent; Obama won district by 55 percent to 44 percent)

Like Childers, Foster first won his House seat in an early 2008 special election then won re-election comfortably in November. Illinois’ 14th, usually votes Republican: Foster, a scientist and businessman, was preceded in the seat by longtime Republican Rep. J. Dennis Hastert, who resigned in 2007 after the Democratic takeover of the House cost him his position as Speaker. But voters in the district, which begins in exurbs of Chicago and stretches distantly into western Illinois, backed favorite-son candidate Obama in the presidential balloting and gave Foster an even larger share of their votes.

• Parker Griffith , Alabama’s 5th District (elected with 51 percent to hold a Democratic open seat; McCain won district by 61 percent to 38 percent)

Griffith’s narrow win over Republican Wayne Parker gave Democrats a key open-seat hold in a conservative-leaning part of northern Alabama that nine-term Democrat Robert E. “Bud” Cramer left open to retire. Griffith, a former state senator, said in a statement Wednesday that he voted “no” on the budget resolution because “it spends too much money across the board.” He also voted against the economic stimulus measure. But the closeness of his 2008 race likely will prompt Republicans to prospect another serious challenge in 2010.

• Frank Kratovil Jr. , Maryland’s 1st District (elected with 49 percent to succeed Republican Rep. Wayne T. Gilchrest, who lost his primary; McCain won district by 58 percent to 40 percent)

Kratovil represents Maryland’s Eastern Shore and parts of exurban Baltimore across the Chesapeake Bay. He was the beneficiary of a fractious Republican primary won by conservative state Sen. Andy Harris over moderate nine-term incumbent Gilchrest — who would end up endorsing Kratovil, then a county prosector, for the general election. Despite the district’s Republican lean, underscored by McCain’s strong showing, Kratovil defeated Harris by less than 1 percentage point.

• Dennis J. Kucinich , Ohio’s 10th District (elected to 7th term with 57 percent; Obama won district by 59 percent to 39 percent)

Kucinich is an outlier on this list because he is a staunch liberal who represents a Democratic-leaning, Cleveland-based district. When Kucinich defies his party’s leadership, it is usually because he believes legislation does not go far enough in promoting his populist agenda on economic and foreign policy issues. Sharply criticized during his 2008 campaign for spending time on quixotic bids for the Democratic presidential nomination that year and in 2004, he slipped to his lowest vote share ever in a re-election bid, but nonetheless won comfortably.

• Betsy Markey , Colorado’s 4th District (defeated Republican Rep. Marilyn Musgrave with 56 percent; McCain won district by 50 percent to 49 percent)

Markey, a businesswoman and former Senate aide, won by a wide margin in 2008 over three-term Republican Musgrave, an outspoken conservative best known for her opposition to same-sex marriage. Markey is expected to face a potentially difficult re-election race next year in northern and eastern Colorado. Following her vote against the budget resolution, Markey said, “We must go further in cutting the projected $1.2 trillion deficit and reining in spending by demanding that each federal department make deep cuts in their budget.”

• Jim Marshall , Georgia’s 8th District (elected to 4th term with 57 percent; McCain won district by 56 percent to 43 percent)

Marshall, who represents Macon and some rural areas in central and southern Georgia, faced serious opposition in 2006, when he won narrowly, and in 2008, when he prevailed handily. The center-right record crafted by the Vietnam War veteran — which includes his steadfast support for the decision by President George W. Bush to use military force in Iraq — has made him one of the most resilient white House Democrats in a region that remains the strongest for the national Republican Party.

• Jim Matheson , Utah’s 2nd District (elected to a 5th term with 63 percent; McCain won district by 58 percent to 40 percent)

Matheson, who represents part of Salt Lake City and vast swaths of eastern and southern Utah, will sometimes vote with Republicans on economic policy and has good relations with the U.S. Chamber of Commerce, a business advocacy groups that typically endorses Republicans for Congress. After narrowly surviving his first re-election bid in 2002, Matheson has increased his vote share in every election since, and appears unlikely to be heavily targeted in 2010.

• Mike McIntyre , North Carolina’s 7th District (elected to 7th term with 69 percent; McCain won district by 52 percent to 47 percent).

McIntyre represents Wilmington, part of Fayetteville and other territory in southeastern North Carolina. His longstanding position in the ranks of conservative-leaning House Democrats has enabled him to win at least two-thirds of the vote in each of his six re-election campaigns.

• Walt Minnick , Idaho’s 1st District (defeated Republican Rep. Bill Sali with 51 percent; McCain won district by 62 percent to 36 percent)

Minnick unseated one-term Republican Sali, a staunch conservative who had antagonized a lot of Republican voters in the Boise region and Idaho’s Panhandle with what many regarded as an abrasive manner. Minnick — a businessman who once served as an aide in the Republican administration of Richard M. Nixon before switching parties — has one of the most conservative voting records among House Democrats during his initial weeks in Congress. Minnick also voted against the economic stimulus law. Still, Minnick will be heavily targeted in 2010; one Republican who is already preparing a bid is Vaughn Ward, a Marine Corps veteran and former Senate aide.

• Harry E. Mitchell , Arizona’s 5th District (elected to a 2nd term with 53 percent; McCain won district by 52 percent to 47 percent)

Mitchell, who represents Scottsdale and his hometown of Tempe in suburban Phoenix, has sometimes sided with Republicans on budget and tax policy. Although his district was represented for 12 years by voluble conservative Republican J.D. Hayworth, whom Mitchell unseated in 2006, the fact that homestate Republican McCain got a modest 52 percent there for president in 2008 suggests that it is a swing district.

• Glenn Nye , Virginia’s 2nd District (defeated Republican Rep. Thelma Drake with 52 percent; Obama won district by 50 percent to 48 percent)

Nye, who previously worked with international development agencies, last year unseated Drake, a two-term incumbent, in a district that includes Virginia Beach. Virginia’s 2nd District historically has leaned more Republican than Democratic — though it shifted in 2008 to back Obama, who became the first Democratic presidential nominee in 44 years to carry Virginia. Nye will have to defend against a likely Republican push to reclaim the seat.

• Gene Taylor , Mississippi’s 4th District (elected to 10th full term with 75 percent; McCain won district by 67 percent to 32 percent)

Republican presidential nominee McCain ran ahead of Obama in 49 districts that also voted to send Democrats to the House. Taylor’s district, based in southern Mississippi, gave McCain the largest vote share among these “McCain-Democratic” districts. But Taylor, who’s focused on defense issues and is long-established as one of the most conservative Democrats, has won by wide margins in all 10 of his re-election contests since his initial victory in a 1989 special election.

• Harry Teague , New Mexico’s 2nd District (elected with 56 percent to take over Republican open seat; McCain won district by 50 percent to 49 percent)

Teague was first elected last year in a mostly rural district in southern New Mexico that had been in Republican hands for nearly three decades, first held by Joe Skeen from 1981 to 2003 and then Steve Pearce from 2003 to 2009. But Pearce’s decision to run for an open Senate seat in 2008 — he won the Republican primary but then badly lost the general election to Democrat Tom Udall — created an opening for conservative-leaning Democrat Teague, an oil well services company owner, in a year when national politics were trending strongly Democratic. The same district that gave McCain a mere 1-point margin over Obama had favored Bush over Democrat John Kerry by 17 points in the 2004 presidential election.