After seeing the gains made by Virginia Republicans on Election Day, Sen. Charles S. Robb (D) and former governor George Allen (R) appeared to be trading the customary roles for their 2000 Senate contest, with the incumbent Robb quickly taking the offensive and Allen, the challenger, adopting a front-runner's stance.

As soon as the GOP claimed its historic majority in the state legislature Tuesday, Robb began jabbing at state Republicans, saying they might "overstep" and alienate voters next year. Robb's supporters aimed directly at Allen, contrasting Allen's hard-charging conservative style with that of his more pragmatic successor, Gov. James S. Gilmore III (R).

Allen, who leads Robb in opinion polls and in fund-raising, sat back comfortably on election night, content to stand by Gilmore's side and praise their "six-year" legacy of conservative triumphs.

The new Republican majority in the General Assembly owes its existence to slim victory margins in four districts. Still, the week's results bolstered the perception--created over a decade of GOP victories--that Robb is launching an underdog's fight 12 months before Virginia voters choose their next senator. The Republicans picked up three seats in the House of Delegates, for a 52 to 47 edge over Democrats; there is one Independent in the House. Republicans maintained their 21 to 19 edge in the Senate.

Democrats looked at Tuesday's returns and admitted they face tough odds, noting that they have yet to figure out a strategy to carry vote-rich suburbs in all parts of the state.

Kevin Mack, executive director of the Democratic Legislative Congressional Committee, which gave heavily to Virginia Democrats in last week's election, said the results showed that the Democrats' campaign for gun control misfired, even in many parts of Northern Virginia where people were supportive.

"I never thought guns was a winner issue," Mack said.

And although Democratic candidates can still run strong in the nearer suburbs, Mack said, Republicans have solidified their hold on outer suburbs in the 1990s.

"Places that used to be Democratic strongholds are now Republican strongholds, and we have to rebuild," Mack said. In populous Northern Virginia, which gave Robb a critical majority in his 1994 campaign, Mack noted that the winning GOP legislative campaigns form a tightening ring around mostly Democratic inner suburbs.

"Fairfax County makes or breaks Chuck Robb," Mack said. "Robb's just got to come out of Fairfax winning, and you can't do it without a concerted effort."

Analysts said the burden will be on the Democrat to make his case.

"Given all the trends that have occurred in Virginia in the 1990s, it is unlikely that Robb can run simply as an incumbent who has done a fairly good job and get elected," said Richmond political scientist Robert D. Holsworth.

"All Allen wants is for the trend to continue," he said. "Democrats need a campaign that can find a message and reenergize the Democratic Party and reach out to the new voters in the suburbs."

Robb, 60, downplayed the effect of Democratic legislative defeats on his own race, saying of the $18 million GOP campaign, "Given the amount of time, energy and resources--particularly resources--it's less than the kind of victory that Republicans were looking for."

"Sometimes," he added, "a close loss of a majority can energize folks."

Fellow Democrats are promising to cast Allen's combative record as governor from 1994 to 1998 as something removed from the mainstream. Several eagerly credited Gilmore's successful centrist approach, dealing a backhanded slap at Allen's more aggressive, failed campaign in 1995 to win a GOP legislative majority.

"George Allen is so far to the right of every credible political figure left in Virginia. I think the comparison to Jim Gilmore is maybe going to hurt George Allen," said Jim Jordan, political director of the Democratic Senatorial Campaign Committee, which lists defending Robb's seat as its No. 1 priority in 2000.

Robb pollster Geoff Garin added his critique of Tuesday's election results, mentioning Robb's polarizing 1994 Republican opponent, Oliver L. North, and 1993 lieutenant governor nominee Michael P. Farris, a leader of the home-schooling movement.

Last week's election, he said, "was a victory for conservatives becoming moderates." Winning Republican candidates, he said, emphasized improving schools and highways over divisive social issues. "These are people who essentially ran away from the George Allen record. They rejected his position on guns, on choice, on the environment, on transportation investments."

"The philosophy expressed by Allen's record," Garin concluded, "reflects more of an Oliver North or Mike Farris Republican than a Jim Gilmore Republican."

Allen, 47, cruised to a landslide election as governor in 1993 on the strength of a promise to end parole and impose truth-in-sentencing in Virginia. Although Allen overhauled the state's welfare and school systems and presided over a booming economy in office, he clashed often with liberal interest groups including teachers unions, civil rights leaders, environmentalists and abortion rights groups.

Voters embraced Allen's folksy conservatism personally but seemed to tire of confrontation when they rejected an Allen program to cut taxes and spending, and returned Democratic lawmakers to the legislature in 1995.

Allen himself is standing back from the fray for now. On Tuesday night, he said of GOP gains, "It's great for next year. We're going to bring the same principles and ideas that Virginia expects and values to Washington with a new, active voice for the U.S. Senate."

Behind the scenes, Allen's camp is searching for ways to answer Democratic attempts to portray him as a hard-edged, rigid conservative. Republicans note, for example, that in his campaign for governor, Allen avoided stating publicly whether he supported Roe v. Wade, the Supreme Court ruling that established a constitutional right to abortion.

Allen's personal popularity remains high across the state, and supporters add that Democrats' attacks on Republicans as extremists have failed before.

"George Allen is a thoughtful conservative and not someone you can box into a boilerplate attack that Democrats are trying to do," campaign spokesman Jay Timmons said.