First lady Laura Bush was the star attraction at a campaign luncheon yesterday for Maryland Rep. Constance A. Morella, a rare fundraising appearance that netted one of the House's most vulnerable Republicans $150,000.

While President Bush and Vice President Cheney have crisscrossed the country this year, bringing in $167 million for GOP candidates and state parties intent on controlling the House and Senate, Mrs. Bush has kept a much lower profile. Morella is the only Republican House member to have landed the first lady; Bush's other six fundraising appearances have been for gubernatorial or Senate candidates.

But the race in the 8th District, one of the nation's most closely watched congressional contests, has attracted a string of political luminaries. Just as the White House's current occupants are helping the eight-term incumbent raise money, their immediate predecessors are helping her Democratic opponent, state Sen. Christopher Van Hollen Jr.

The election will help determine whether Democrats recapture a House majority. The latest independent poll, conducted Oct. 27-28 by Potomac Inc., showed the outcome to be too close to call.

Former president Bill Clinton will headline a rally tomorrow to benefit Van Hollen and the Democrats' gubernatorial nominee, Lt. Gov. Kathleen Kennedy Townsend. An earlier fundraising event featured Sen. Hillary Rodham Clinton (D-N.Y.).

Van Hollen and Townsend are counting on large Democratic turnout in Montgomery and Prince George's counties, particularly among African American voters, to help them eke out victories. Democrats believe that the former president is a huge asset in motivating black voters to go to the polls.

Though Van Hollen's and Townsend's interests dovetail, that is not the case with Morella and the Republican gubernatorial nominee, Rep. Robert L. Ehrlich Jr. Yesterday, Morella's camp distanced itself from the more conservative Ehrlich, the second time it has done so this campaign season.

Morella took issue with a state GOP mailing that quotes her talking about "my friend Bob Ehrlich" and features a picture of the two together. Her campaign manager said yesterday that the party had not told him in advance about the brochure. Had he been contacted, Tony Caligiuri said, he would not have approved it.

Some of Morella's strongest endorsements come from pro-choice, gun control and gay rights groups targeting Ehrlich for defeat. The Human Rights Campaign is even running radio ads that declare Morella the true Republican moderate. Ehrlich, the spot says, is a pretender.

"We had no warning, no nothing, and Connie is very concerned," Caligiuri said.

Paul Ellington, executive director of the Maryland Republican Party, offered no apology. "We didn't contact the campaign because we didn't feel that we had to. We're proud of Connie Morella, and we're proud of Bob Ehrlich," he said.

The Laura Bush fundraiser was arranged by longtime family friend Shelly Kamins, a Potomac real estate investor and Bush's Maryland finance co-chairman during the 2000 election. The event, which was closed to the media, drew about 250 people to Kamins's home. Big-dollar donors lunched on takeout from Chicken Out Rotisserie.

The fact that Laura Bush took the unusual step of coming to Morella's district signals a troubled campaign, Democrats maintain.

"It's the latest indicator that Morella is quite vulnerable and that the national Republicans are going to go to any length to help her," said Kim Rubey, a spokeswoman for the Democratic Party's congressional campaign committee.

With just six days to go to the election, both candidates are concentrating on mobilizing supporters amid a last-minute campaign advertising blitz. For weeks, Morella and the Republican Party's congressional campaign committee have pounded Van Hollen on the air, questioning his character and commitment to progressive ideals. By contrast, Van Hollen's television and radio commercials have focused largely on his 12-year record in the state General Assembly.

Morella's popularity has allowed her to go on the attack, driving up voters' negative views of her opponent without much of a boomerang effect, according to Keith Haller, who conducted the latest independent poll.

"Her popularity is still at record levels, despite throwing bombs Van Hollen's way," Haller said. "This is a razor-thin race, and either candidate can win it."

Still, no incumbent likes to be below 50 percent in polls so late in a campaign, in part because undecided voters in tight races traditionally break for challengers. Haller's survey has Morella at 44 percent and Van Hollen at 42 percent -- a statistical dead heat once the margin of error is factored in.

"If you are a long-term incumbent and you haven't broken 50 this late in the game, that suggests that voters are looking at voting for someone else," explained Amy Walter, who tracks House races for the Cook Political Report. "That they are sitting in the undecided column is troublesome for her."

First lady Laura Bush attended a fundraiser for 8th District Rep. Constance A. Morella.