VIRGINIA BEACH, May 19 -- When some of the country's top political handicappers drew up their charts of vulnerable House incumbents at the beginning of this year, Rep. Thelma D. Drake (R-Va.) was not among them. Now she is.

President Bush carried her district with 58 percent of the vote in 2004, but strategists say his travails are part of the reason the freshman lawmaker now has a fight on her hands. He swooped into town briefly Friday for a closed-door fundraiser for Drake but made no public appearances.

Drake, who won with ease two years ago, is not alone. With approval ratings for Bush and congressional Republicans at a low ebb, GOP strategists see signs of weakness where they least expected it -- including a conservative, military-dominated suburb such as Virginia Beach -- and fear that their problems could grow worse unless the national mood brightens.

Some veterans of the 1994 GOP takeover of Congress see worrisome parallels between then and now, in the way once-safe districts are turning into potential problems. Incumbents' poll numbers have softened. Margins against their Democratic opponents have narrowed. Republican voters appear disenchanted. The Bush effect now amounts to a drag of five percentage points or more in many districts.

The changes don't guarantee a Democratic takeover by any means, but they are creating an increasingly asymmetrical battlefield for the fall elections: The number of vulnerable Democratic districts has remained relatively constant while the number of potentially competitive Republican districts continues to climb.

Stuart Rothenberg, editor and publisher of a political newsletter, now has 42 Republican districts, including Drake's, on his list of competitive races. Last September, he had 26 competitive GOP districts, and Drake's wasn't on the list. "That's a pretty significant increase," he said. "The national atmospherics are making long shots suddenly less long."

At the Cook Political Report, Amy Walter has revised an analysis of the battle for control of the House, taking into account the sour mood toward Republicans nationally as a potentially significant factor in races that might otherwise turn on local issues, candidate performance or the size of campaign war chests.

"In a nationalized election, the typical laws of gravity get thrown out the window," Walter said. "Under-funded candidates beat better-funded candidates, and entrenched incumbents lose to first-time challengers."

Republicans said these trends in recent polling data are an early alert, not a cause for panic. Their strategists argue that their incumbents will not be caught by surprise, as many Democrats were in 1994, when they were swept from power in the House after 40 years.

House Republican campaign officials are taking steps to protect their vulnerable candidates with money, opposition research, negative television ads and campaign messages designed to fly below the worst of the national turbulence. But they know there is only so much they can do if Bush's approval rating stays below 40 percent and voters continue to say they want a change in direction.

Drake, a first-term representative, isn't yet among the most endangered GOP incumbents. But she is one of many -- and not just inexperienced lawmakers -- who could be at risk if there is an anti-Republican wave in the fall. Among House incumbents added to some GOP watch lists in recent months are veteran Reps. Nancy L. Johnson (Conn.), Deborah Pryce (Ohio), Charles Bass (N.H.), J.D. Hayworth (Ariz.) and Richard W. Pombo (Calif.).

The National Republican Congressional Committee chairman, Thomas M. Reynolds (R-N.Y.), acknowledged Tuesday that the national mood has accelerated campaign planning by many incumbents. While vowing that Republicans will maintain their House majority in the fall, regardless of the national climate, Reynolds said, "Members [are] paying much more attention and putting together campaigns earlier."

Virginia's 2nd Congressional District, home to the U.S. Navy's Atlantic Fleet, generally is solid Republican territory. Bush won the district with 58 percent of the vote in 2004, and Drake was elected with 55 percent. But Democratic Gov. Timothy M. Kaine won the district in his victory last November, and the fact that Drake, a 56-year-old former real estate agent and state legislator, is in her first term adds to the list of GOP worries.

Around Virginia Beach, Republicans believe the race is Drake's to lose but say she nonetheless faces a long six months. "I think Thelma is going to have to campaign hard, and she will," said state Del. Leo C. Wardrup Jr., who helped recruit Drake into Congress.

Her opponent, Democrat Phil Kellam, Virginia Beach commissioner of revenue, believes the most effective line of attack is to paint Drake as a loyal vote for the president at a time when Bush's popularity has declined even in red states he carried in 2004. "She is grafted to this president," Kellam said.

Drake did not attend Friday's fundraiser luncheon with the president, but her aides said the reason had nothing to with Bush's political standing. They said she was in Washington for a vote on legislation affecting military families.

White House officials acknowledge that the president's time is too valuable to waste on safe incumbents. In some cases, the boost from a presidential fundraiser can turn a potentially competitive race into a relatively safe seat, but that was not the expectation Friday. "She's got a real competitive race," a Bush adviser said of Drake, speaking on the condition of anonymity in order to give a candid assessment.

After helping Drake pick up about $475,000, Bush flew to Kentucky to raise money for another embattled Republican, Rep. Geoff Davis, who is being challenged by former Democratic representative Ken Lucas.

Democrats do not yet consider Drake among their best targets, but they hope to make her one. The national party began running radio ads here this week, attacking Drake for backing Bush's plan to revamp Social Security. The liberal group MoveOn.org says it has spent more than $100,000 running television ads attacking her ethics.

Drake said the Democrats' strategy of trying to use Bush against her won't work. "I would much rather think like President George Bush than to think like Senator Ted Kennedy, [Democratic Party Chairman] Howard Dean or [House Minority Leader] Nancy Pelosi," she said in an interview from her Capitol Hill office.

Although Drake quickly earned a seat on the House Armed Services Committee, a coveted spot for a district with some of the world's largest military bases, Kellam hopes to turn the district's large military presence to his advantage.

In an interview, he said he does not support a rapid pullout of troops from Iraq, but he criticized Drake, saying she has failed to ask tough questions about the conduct of the war. "Can you tell me that the Congress has scrutinized the Department of Defense as much as is necessary?" he asked.

Kellam has also seized on the fate of the huge Oceana Naval Air Station, targeted for possible closure by a congressional commission. He accused Drake and other Virginia Republicans of failing to do enough to keep the station's jets in the area.

Drake responded angrily, saying that Virginia's Democrats and Republicans have worked together to protect the base. She also said she has worked hard on Iraq, visiting troops twice since taking office, and called Kellam's criticisms "absolutely false, untrue [and] deliberately misleading."

Drake's goal will be to rebut Kellam's criticisms and prove to constituents that she has delivered for them. Kellam's hope is that factors beyond Drake's control will overwhelm the customary political leanings of the district.

Balz reported from Washington. Special correspondent Chris Cillizza in Washington contributed to this report.

Commentary: