A new poll released Wednesday shows Americans are nearly evenly split on whether to allow gay and lesbian couples to marry.

The poll conducted by The Pew Research Center for the People & the Press found 45 percent of adults favor marriage equality, while 46 oppose it. That's an increase of 3 percent over last year's poll, which found opponents outnumbered supporters 48% to 42%.

According to the poll, the issue breaks down along political and geographic lines.

Support is lowest in the Midwest (40% favor) and the South (34%). But a majority of adults favor gay marriage in the Northeast (59%) and the West (56%).

Support is highest among Democratic voters. Fifty-seven percent of Democratic voters support marriage equality. Support from Independent voters increased by 7 percent from last year, from 44% to 51%, while Republican support dropped by 1 percent, from 24% to 23%.

Other national polls, including an AP poll conducted late last year, concluded that a narrow majority of Americans favor legalizing gay marriage. And, according to the Human Rights Campaign (HRC), the nation's largest gay rights advocate, a majority of people in 17 states now support marriage equality.