Gov. Mark Dayton is intensifying pressure on legislators to legalize same-sex marriage this year.

The DFL governor spoke personally about the issue to House Democrats on Wednesday, and his campaign sent out an appeal urging supporters to ask their legislators to support legalized marriage.

"I realize this is a difficult decision for many of them," Dayton said upon leaving a closed-door meeting of DFL House members.

Advocates on both sides of the issue have spent months pressing their visions. They've conducted Capitol rallies, traveled the state and held dozens of private meetings with legislators to garner votes.

In the coming days, the full House and Senate are expected to take votes that will show what some members have made of all the pressure.

Opponents of same-sex marriage say Dayton and other advocates are pressing fellow DFLers into a vote that could come at great political peril.

"It's further evidence that Governor Dayton and his Democratic allies are trying to force same-sex marriage on Minnesota," said Autumn Leva, a spokeswoman for Minnesota for Marriage, which is working to defeat the measure. "It seems like Governor Dayton is encouraging legislators to go against the wishes of constituents who voted them into office."

For legislators, the arguments on both sides are nuanced and emotional.

Last year, Minnesota voters rejected a constitutional amendment to ban same-sex marriage. But supporters of keeping marriage only as the union of a man and a woman say that does not mean Minnesotans are ready to accept same-sex marriage.

Dayton is pressing the case that Minnesotans are ready. He said in a recent interview that he would try to persuade uneasy legislators to support same-sex marriage as the vote comes to the fore. "I have told them I will weigh in where they think I can be most effective as the vote comes close," the governor said in the interview.

On Wednesday, he took some of those steps.

As he met with legislators privately Wednesday to talk about the coming end-of-session budget negotiations, he also brought up his belief that it is time to legalize same-sex marriage.

He said that during the meeting, he reminded House members of John F. Kennedy's 1955 book "Profiles in Courage," a collection of sketches about U.S. senators who took difficult stands, and of what he believes is the right thing to do in this case.

Dayton was even more ardent in pressing his case in an e-mail to supporters.

"I believe all of us should have the freedom to marry legally the person we love," he wrote. "But our opponents won't let go. They're targeting legislators with harsh mailings, pressuring them to vote no. They're threatening to go after members who vote 'yes' in the coming elections."

Dayton called the measure "historic legislation" and urged supporters to turn up the volume at the State Capitol.

"Urge lawmakers in St. Paul to follow their consciences and pass the freedom to marry," he said in the e-mail. "We cannot legislate love. Committed, same-sex Minnesota couples deserve to make their own decisions for their own families. It's a simple, yet profound ideal."

rachel. stassen-berger@startribune.com Twitter: @RachelSB baird.helgeson@startribune.com 651-925-5044