Republicans surged to victory in governors' races in Virginia and New Jersey on Tuesday, wresting control from Democrats in both states with support from independent voters.

Conservative Republican Bob McDonnell's victory in the Virginia governor's race over Democrat R. Creigh Deeds and moderate Republican Chris Christie's ouster of unpopular New Jersey Gov. Jon Corzine was a double-barreled triumph for a party looking to rebuild after being booted from power in national elections in 2006 and 2008.

Republican Chris Christie, left, and his wife, Mary Pat, greet supporters after his victory over Jon Corzine, the incumbent New Jersey governor. (Henry Ray Adams/Associated Press)Meanwhile, Democrat Bill Owens captured a Republican-held vacant 23rd Congressional District seat in New York in a race that highlighted fissures in the Republican Party and illustrated hurdles it could face in capitalizing on any voter discontent with Obama and Democrats next fall.

A slew of cities selected mayors, including New York, which gave Michael Bloomberg a third term in a closer-than-expected race against a Democratic challenger. Bloomberg defeated William Thompson Jr. 51 per cent to 46 per cent — a difference of fewer than 51,000 votes

McDonnell, a former state attorney general, had about 60 per cent of the vote in Virginia with most precincts reporting. He takes back the governor's office after eight years of Democrat control.

With 97 per cent of New Jersey precincts reporting, Christie had 49 per cent of the vote compared with 44 per cent for Corzine. Independent candidate Chris Daggett, who at one point had been feared as a potential spoiler, had about five per cent.

The Associated Press exit polls indicated that nearly a third of voters in Virginia described themselves as independents, and nearly as many in New Jersey did. They preferred McDonnell by almost a 2-1 margin over Deeds in Virginia, and Christie over Corzine by a similar margin.

Last year, independents split between Obama and Republican John McCain in both states.

Republican governor-elect Bob McDonnell waves to the crowd at his victory party in Richmond, Va., on Tuesday. (Steve Helber/Associated Press)In both states, the surveys also suggested the Democrats had difficulty turning out their base, including the large numbers of first-time minority and youth voters whom Obama attracted.

The outcomes were sure to feed discussion about the state of the electorate, the status of the diverse coalition that sent Obama to the White House and the limits of the president's influence on the party's base of support and on moderate current lawmakers he needs to advance his legislative priorities.

His signature issue of health-care reform was dealt a blow hours before polls closed when Senate Democratic leader Harry Reid signalled that Congress may not complete health care legislation this year, missing Obama's deadline and pushing debate into a congressional election year.

The president had personally campaigned for Deeds and Corzine, seeking to ensure that independents and base voters alike turned out even though he wasn't on the ballot.

But the Democrats racked up a win in the special congressional election held in a heavily Republican district in northern New York. With 88 per cent of the precincts reporting early Wednesday, Owens defeated businessman Doug Hoffman, the Conservative Party candidate, 49 per cent to 46 per cent.

Dierdre Scozzafava, a moderate Republican, withdrew from the race Saturday. Hoffman started at a distant third and was viewed as a spoiler at best, cutting away at Scozzafava and opening the door for Owens.

But prominent Republicans such as former vice-presidential candidate Sarah Palin and Minnesota Gov. Tim Pawlenty endorsed Hoffman instead of the party-picked Scozzafava.