Louisiana Senator Mary Landrieu has said that she has to honor the views of her constituents on gay marriage.

Landrieu is among the final four Democratic senators who remain opposed to marriage equality after a flurry of senators shifted their public stance in recent weeks. The other three holdouts are Mark Pryor of Arkansas, Joe Manchin of West Virginia and Tim Johnson of South Dakota.

“I'm a lot, you know, like other people said my views have evolved on this,” Landrieu told CBS affiliate KNOE. “But my state has a very strong constitutional amendment against gay marriage and I think I have to honor that.”

According to a report released last week by the UCLA's School of Law's Williams Institute, only 31 percent of Louisianians support marriage equality. While that's a 10 percent increase since 2004, it is still the lowest among the 50 states.

Currently, 53 U.S. senators support gay nuptials, including two GOP senators: Rob Portman of Ohio and Mark Kirk of Illinois.

(Relate: Support for gay marriage has increased in all 50 states.)