Independents who swept Barack Obama to a historic 2008 victory broke big for Republicans on Tuesday as the GOP wrested political control from Democrats in Virginia and New Jersey, a troubling sign for the president and his party heading into an important midterm election year.

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.

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 signaled that Congress may not complete health care legislation this year, missing Obama's deadline and pushing debate into a congressional election year.

Elsewhere on Tuesday, Maine voters weighed in on same-sex marriage in a closely watched initiative, and New York and California picked congressmen for two vacant seats. A slew of cities selected mayors, and Ohio voted on allowing casinos.

The president had personally campaigned for Deeds and Corzine, seeking to ensure that independents and base voters alike turned out even if he wasn't on the ballot. Thus, the losses were blots on Obama's political standing to a certain degree and suggested potential problems ahead as he seeks to achieve his policy goals, protect Democratic majorities in Congress and expand his party's grip on governors' seats next fall.

Interviews with voters leaving polling stations in both states were filled with reasons for Democrats to be concerned and for Republicans to be optimistic, particularly about independents — the crown jewel of elections because they often determine outcomes.

--Full story continues below--