A new poll released Monday shows support for gay marriage to be at an all-time high.

According to the Washington Post-ABC News poll, 58 percent of Americans now believe such unions should be legal, while 36 percent remain opposed. That is a 21 percentage point increase over the past decade.

One question in the survey was directly aimed at the U.S. Supreme Court's upcoming pair of cases related to the issue.

When asked, “Do you think each state should make its own law on whether same-sex marriage is legal or illegal there, or do you think this should be decided for all states on the basis of the U.S. Constitution?” 64 percent of respondents answered that the question should be decided on the basis of the U.S. Constitution.

“This latest poll underscores America's dramatic and stunning embrace of the freedom to marry, and says to decision makers – lawmakers, judges, and even justices – that it is time to end marriage discrimination,” said Evan Wolfson, founder and president of Freedom to Marry. “With a super-majority of Americans now supporting the freedom to marry, and majority support in nearly every segment of the public, the freedom to marry's time has, indeed, come.”

Support among young adults under 29 also hit a new record: 81 percent.

But only 44 percent of adults 65 years and up support marriage equality. Fifty percent believe it should be illegal.

A majority of Democrats (72%) and independents (62%) favor such unions. And while Republican opposition has decreased 13 percent since 2004, a majority (59%) still remain opposed. Only thirty-four percent of Republicans support giving gay and lesbian couples the right to marry.

The poll also found that a large majority (62%) of Americans believe being gay is not a choice.