Florida Senator Marco Rubio, a candidate for the Republican presidential nomination, said Wednesday that he's opposed to a constitutional amendment defining marriage as a heterosexual union.

In the wake of the Supreme Court's ruling striking down marriage bans in all 50 states, several GOP presidential candidates – including Texas Senator Ted Cruz and Wisconsin Governor Scott Walker – have endorsed such an amendment as a means to reverse the court's decision.

“I don't support a constitutional amendment. I don't believe the federal government should be in the marriage regulation business,” Rubio told reporters after speaking to an audience at the Cedar Rapids Country Club in Iowa.

“We can continue to disagree with it. Perhaps a future court will change that decision, in much the same way as it's changed other decisions in the past.”

Rubio added that he remains opposed to marriage equality. In that respect he remains in lockstep with his Republican rivals.

“[M]y opinion is unchanged, that marriage should continue to be defined as one man and one woman. The decision is what it is, and that's what we'll live under.”

“I disagree with the decision on constitutional grounds,” he added. “Irrespective of how one may feel about the definition of marriage, we're still all Americans.”

(Related: Marco Rubio: Being gay is not choice.)