Maryland Senate President Thomas V. Mike Miller Jr. (D-Calvert), an opponent of same-sex marriage, predicted Thursday that the bill would clear the General Assembly in next year’s session.

Gov. Martin O’Malley (D) announced last week that he would sponsor the legislation, which failed last session in the House of Delegates after passing in Miller’s chamber.

In an interview, Miller said O’Malley’s sponsorship would matter “not a whole lot” when the legislature debates the bill again.

A bigger factor, Miller reasoned, is what has happened in the aftermath of the legislature’s passage of a bill this year that would grant in-state university tuition rates to illegal immigrants. Opponents of that bill took advantage of a provision in the state Constitution that allows citizens to petition just-passed legislation to a statewide vote.

The relative ease with which the tuition bill was petitioned to the ballot should make clear to everyone that the same thing will happen with a same-sex marriage bill — which, in turn, will make it easier for some wavering delegates to vote for it, Miller reasoned.

“I don’t anticipate it is going to be that difficult in the House,” Miller said.

Supporters of the bill said they were two votes shy of a majority in the House in this year’s session. A vote was never taken on the floor.

Miller said the votes in his chamber would likely break the same way next year as this year. The bill passed the Senate 25 to 21, with one same-sex marriage opponent, Sen. Joanne C. Benson (D-Prince George’s), missing the vote.

If Miller is correct, both the same-sex marriage and immigrant tuition legislation would appear on the statewide ballot in November 2012, producing what Miller predicted would “probably be one of the largest turnouts in the state of Maryland.”

Miller said he thinks both measures are likely to fail when put to the public. The vote on same-sex marriage is likely to be the closer of the two, he said.

Supporters of the immigrant tuition bill have the tougher battle, Miller said. “I’m going to work for it,” he said, “but in tough times, people vote their biases, they vote their prejudices.”