According to a new poll published Monday, support for same-sex marriage in the United States has hit an all-time high.

Gallup's annual Values and Beliefs poll conducted May 3-7 found that 64 percent of Americans believe that marriage equality should be legal.  That's a 3 percent increase over last year.

The new high comes roughly two years after the Supreme Court in Obergefell found that gay and lesbian couples have a constitutional right to marry.

Support for such unions has more than doubled since Gallup first polled on the issue in 1996 (64% vs. 27%), and support among Republicans has nearly tripled, from 16 percent in 1996 to 47 percent today.

A majority (55%) of U.S. Protestants, including all non-Catholic Christians, for the first time support marriage equality.

“Support for gay marriage has gradually increased over the past two decades, reaching majority support with new groups, as it did with senior citizens in 2016 and Protestants this year,” researchers wrote in releasing their findings. “Republicans' support for gay marriage is also at a new high and could trend toward majority support in the near future.”