(CNN) -- Apparent White House division over gay marriage - with Vice President Joe Biden saying Sunday that he is "absolutely comfortable" with the idea, going further than President Obama has on the issue -- mirrors a nation that is evenly divided on the matter. Recent polls show that about half of Americans favor legalized gay marriage, while half oppose it, with support for the idea gaining significant ground over the past 15 years.
Pew's latest polling on the issue, conducted late last year, found that 46% of Americans support favor allowing gays and lesbians to marry legally, while 44% are opposed. Support for gay civil unions is substantially higher, with a clear majority of Americans supporting such arrangements.
Feelings about gay marriage correlate to various religious traditions and levels of religiosity, with those nonaffiliated with any religion most supportive of gay marriage. It's worth noting the dramatic recent shifts on the issue among Roman Catholics, whose ranks include Biden.
Despite the Roman Catholic Church's rigorous opposition to gays getting the right to marry, Pew found that Catholics support gay marriage by a margin of 52% to 37%. That's a shift from 2010, when just 46% of Catholics favored gay marriage.
Among white Catholics, support is even higher at 57%, while Hispanic Catholics are evenly divided.
The religious group most opposed to gay marriage is white evangelical Protestants, among whom 74% oppose it, according to Pew. Sixty-two percent of black Protestants, a key part of President Obama's political base, also oppose gay marriage.
After Biden voiced support for gay marriage, a senior Obama campaign adviser said there was no difference on the issue between the vice president and the president, who once said he opposed gay marriage but has since said his views on the matter are "evolving."
"What the VP said - that all married couples should have the same legal rights - is (precisely) POTUS' position," said David Axelrod, a senior adviser to Obama's re-election campaign, in a Twitter message.
The issue has gotten attention recently as North Carolinians prepare to vote Tuesday on a ballot initiative that would amend the state constitution to ban gay marriage, reinforcing a state law banning such unions. The Rev. Billy Graham has endorsed the measure, while former President Bill Clinton has taped a robo call opposing it.