WASHINGTON — President Barack Obama's political influence a year after his election is being tested as voters cast ballots in Virginia and New Jersey, two states he's worked hard to keep in Democratic hands. A handful of congressional and mayoral races and a same-sex union initative also are among the featured face-offs this Election Day.

Obama has sought to ensure that Democrats not only win the governor's races but also pick up a GOP-held congressional seat in upstate New York. In doing so, Obama raised the stakes of a low-enthusiasm off-year election season — and risked political embarrassment if any lost.

All three could.

While political insiders in Washington and elsewhere focused on the political implications of the governors races in Virginia and New Jersey, discussions on Twitter focused on the same-sex union initiative in Maine, with the phrases "VoteNoOn1" and "Maine" landing in the site's top trending topics. The measure would repeal a bill passed by the Legislature allowing same-sex marriages.

Heading into Tuesday's elections, Democrat gubernatorial candidate R. Creigh Deeds was trailing Republican Bob McDonnell in polls by double digits in Virginia. In a three-way race in New Jersey, Democratic Gov. Jon Corzine was in a close race with Republican Chris Christie and independent Chris Daggett. And in the race to fill the vacant 23rd Congressional District seat in New York, Democrat Bill Owens was in a tight fight with conservative Doug Hoffman after the GOP's hand-picked candidate bowed out over the weekend.

Elsewhere, California Lt. Gov. John Garamendi is expected to maintain the Democratic Party's hold on the open 10th Congressional District seat near San Francisco, while New York Mayor Michael Bloomberg is expected to cruise to a third term. Atlanta, Houston, Boston, Detroit and Pittsburgh also will elect mayors, while voters in Maine and Washington weigh in on same-sex unions and voters in Ohio decide whether to allow casinos.

To be sure, it's easy to overanalyze the results of such a small number of elections in a few places. The results will only offer hints about the national political landscape and clues to the public's attitudes. And the races certainly won't predict what will happen in the 2010 midterm elections.

"The results of these elections tend to be overread," former Obama campaign manager David Plouffe said Tuesday on NBC's "Today." "These are local races. There's 18,000 lifetimes between now and next November."