Republicans and Democrats engaged Tuesday in the first official skirmish over a controversial constitutional amendment to ban same-sex marriage — the first of many heated battles that are expected during the weeks leading up to a July vote.

At a Senate Judiciary Committee hearing before a standing-room-only audience, Republicans sought to portray the acceptance of same-sex marriages as a growing national crisis that requires immediate Congressional action. On the other side of the dais, Democrats criticized the GOP for trying to score political points in a presidential election year in which control of Congress and the White House is on the line.

“The American people should understand that this continuing spectacle is designed to enhance the political prospects of President Bush and some Republicans in the House and Senate, and to raise the national profile of some state office holders,” said Sen. Patrick Leahy, the senior Democrat on the Judiciary Committee.

Republican leaders announced last week the Senate would turn its attention to the issue July 12 — two weeks before Democrats convene in Boston to nominate Massachusetts Sen. John Kerry as their presidential nominee.

Originally, Republicans had planned to address the constitutional issue this fall, before Congress adjourned for the November election. But a Republican involved in the planning process said that the party instead settled on the July date so that the GOP did not appear to be raising the subject for political purposes.

Even though the constitutional amendment is not expected to attract the 67 Senate votes needed for approval, Majority Leader Bill Frist (R-Tenn.) and Republican Conference Chairman Rick Santorum (R-Pa.) both have stated that it will give voters an opportunity to learn lawmakers’ opinions on the issue.

The decision to schedule the vote for July was also prompted by a concern among some Republicans that unless immediate action was taken, then they would have to wait until next year to address this issue, said a senior GOP aide who requested anonymity.

At the hearing, Senate Judiciary Chairman Orrin Hatch (R-Utah) said he believes that “traditional marriage … is under attack” — a common theme expressed by many in the GOP who support a constitutional ban. Hatch also criticized the Massachusetts Supreme Court for sanctioning same-sex marriages in a decision that was followed by officials elsewhere.

“Four unelected judges in effect imposed this experiment on the entire nation,” Hatch said. “Courts and renegade public officials, not conservative activists, have made this a national issue, and if we are to protect and strengthen the institution of marriage, there appears to be no way around a constitutional solution to this problem.”

Democrats, however, roundly criticized the Republican leadership’s decision to forgo a vote in the Judiciary Committee in favor of bringing the measure directly to the Senate floor.

“Trying to write discrimination into the Constitution is bad enough, but throwing the Senate’s rules out the window and proceeding with a discriminatory amendment that the majority of Americans don’t want and a majority of Senators don’t support, solely for the purpose of trying to score points in a presidential election campaign, demeans this institution and all who have served in it,” said Sen. Edward Kennedy (D-Mass.).

But Hatch defended the GOP’s decision to move the bill to the floor in July, saying that his committee has already held four hearings on the subject. He also scoffed at Democratic suggestions that the process was moving too quickly.

“Everybody knows where they stand on that amendment, and if they don’t, then they have got to find out,” Hatch said. “Why go through an unnecessary, prolonged, bitter delay when the leader [Frist] feels this is an appropriate way to bring it — and I think it probably is in this case.”

Still, Democrats used the hearing to criticize Hatch’s stewardship of the committee, arguing that he has focused the panel’s resources on trying to approve constitutional amendments banning same-sex marriage and flag-burning rather than concentrating on more important issues such as the allegations of abuse at the Abu Ghraib prison and oversight of the FBI.

“I am disappointed by the committee’s priorities,” Leahy said. “While the Bush administration has to apologize for its errors and abuses that have made the American people less safe, this committee spends its time on proposed constitutional amendments to ban gay marriage and flag desecration.”

Hatch dismissed the Democrats’ complaints as merely frustration at being unable to dictate the committee agenda.

“If you don’t run it exactly the way they want it run, then of course they don’t like it,” he said. “Unless you go along with what they want, they are going to be nasty and mean. It is just that simple.”

Sen. John Cornyn (R-Texas), a member of the Judiciary panel, defended Hatch and accused Democrats of trying to use the committee for their own political gain.

“Well, if it were left up to them, they would shut the committee down,” Cornyn said. “I support the chairman and his attempt to conduct business and to try to get some of the these issues heard.”