Voters are casting ballots in a handful of key elections in the United States on Tuesday, including the mayorship of New York City and the governorship of neighboring state New Jersey.

In the year after a presidential election in the U.S., there are not as many elections across the country. But the states of New Jersey and Virginia, both in the eastern part of the country, are electing governors, while large and influential cities including New York, Atlanta, Boston, Houston and Miami, are electing mayors.

In New Jersey, a state that borders New York City, incumbent Governor Chris Christie, a Republican, is expected to cruise to re-election. He has emphasized his appeal across political lines to independents and Democrats, possibly with an eye to running for president in 2016.

In the mid-Atlantic state of Virginia, surveys show a staunch Republican conservative, Attorney General Ken Cuccinelli, is fighting an uphill battle for the governor's seat against business entrepreneur Terry McAuliffe. He is a former national Democratic Party leader and close confidant of former President Bill Clinton and his wife, former Secretary of State Hillary Clinton.

Political analysts in the U.S. are looking for clues from Tuesday's results about congressional elections across the country one year from now, when all 435 members of the House of Representatives face voters and a third of the 100-member Senate does as well.

In New York City, wealthy independent mayor Michael Bloomberg is expected to be replaced by Democrat Bill de Blasio, in a majority-Democrat city that, ironically, has not elected a Democratic mayor since 1989. He has a wide lead over Republican Joe Lhota, a one-time deputy mayor to Bloomberg's predecessor, Rudolph Giuliani. Bloomberg is prohibited by law for running for a fourth term.