Democrats on Wednesday celebrated hard-fought wins in governors' races in Virginia and New Jersey that underlined the political troubles of President George W. Bush and Republicans heading into next year's congressional elections.

Democrats retained governor's offices in conservative Virginia and Democratic-leaning New Jersey on Tuesday after sometimes nasty campaigns. They also dealt California's Republican Gov. Arnold Schwarzenegger an across-the-board

defeat on four ballot initiatives he had championed.

The loss in Virginia was a personal setback for Bush, who put his declining political capital on the line with an election-eve visit on behalf of Republican former attorney general Jerry Kilgore -- only to see him soundly defeated by Democratic Lt. Gov. Tim Kaine.

With Bush's popularity at the lowest level of his presidency, the results helped giddy Democrats claim momentum one year before elections to decide control of both chambers of the US Congress and 36 governorships.

"Yesterday the election was a shot across the bow to George Bush," said New York Sen. Chuck Schumer, head of the Democratic Senate campaign committee, who called the results "a clear repudiation of Bush" and the Republican agenda.

Republicans cautioned against reading too much into the results, saying the elections produced no signs of widespread anti-incumbent sentiment. Redistricting initiatives that could have hurt incumbents in Ohio and California went down to defeat and no governors' offices changed parties.