WASHINGTON – The Senate voted 65-33 Tuesday to give gays and lesbians protection under the federal hate crime law, and officials said a debate was likely next month on a far more controversial measure to amend the Constitution with a ban on homosexual marriages.

Taken together, the developments signaled the full Senate is moving onto politically charged terrain less than five months before the fall elections, and came on a day that President Bush renewed his opposition to gay marriages.

Maine Republican Sens. Olympia Snowe and Susan Collins voted in favor of the amendment.

“Before you get to marriage, you’ve got to get over hate, and today the Senate did,” said Sen. Gordon Smith of Oregon, the leading Republican advocate of hate crimes legislation that has cleared the Senate three times in recent years but has yet to pass in the House.

“When someone is being stoned in the public square, we should all come to their rescue, and that includes the federal government,” he added.

Sen. Edward M. Kennedy of Massachusetts, the leading Democratic supporter of the bill, said hate crimes amount to “domestic terrorism plain and simple, and it’s unacceptable.” He urged the administration to swing behind the proposal.

Current law permits the federal government to assist local and state authorities prosecuting limited types of crimes committed on the basis of the victim’s race, religion or ethnic background. The legislation approved in the Senate would broaden it on two counts, allowing federal involvement in many more types of crimes, and adding sexual orientation, gender and disability to the list of covered categories.

The provision was attached to a $422 billion defense bill that is making its way toward passage.

While previous efforts to approve stand-alone hate crimes bills have failed, Smith and Kennedy prevailed in two earlier attempts to attach the proposal to other legislation.

Both times, though, in 1999 and 2001, the hate crimes provisions were jettisoned during final House-Senate negotiations, in part at the insistence of House conservatives. Smith indicated he wouldn’t be surprised if that happened again. “I’ve not been told it will be stripped out,” he said. “There’s no guarantee it won’t be, and there’s a real possibility it will be.”

Forty-seven Democrats were joined by 18 Republicans in voting for the proposal. All 33 votes in opposition came from Republicans.

White House spokeswoman Claire Buchan declined to say what Bush’s position is.

“The president believes anyone who commits a violent act should receive swift and sure punishment, and that all violent crime is hate crime,” she said. “The president believes all individuals should be treated fairly and equally under the law.”

While hate crimes legislation has been a perennial issue in Congress in recent years, the drive to amend the constitution to ban gay marriages is a relatively new effort.

The Human Rights Campaign, an organization that supports gay rights, issued a statement during the day saying it had learned the measure would be brought to the Senate floor for a debate in the second week of July. Several GOP officials who spoke on condition of anonymity confirmed that timetable was likely.

Bush urged Congress earlier this year to approve an amendment, and Republican officials said the White House had recently been lobbying for a vote on it.

Some Republican strategists contend the issue could present a difficult political choice to Democrats, who could be pulled in one direction by polls showing that a majority of voters oppose gay marriage, and pulled in the other by homosexuals voters and social liberals who support it.