New York Sen. Charles Schumer claimed Monday that "there ought to be limits" on First Amendment rights, while arguing in favor of Democrat-backed legislation that would require full disclosure of big-money donors behind election campaign advertising.

Schumer, the No. 3 Senate Democrat, was pushing for lawmakers to consider the Disclose Act, which would require organizations pouring hundreds of millions of dollars into campaign ads to disclose their top donors and the amounts they spend. Opposition from Republicans, however, prevented Democrats from getting the 60 votes needed to bring the act to the Senate floor.

"I believe there ought to be limits because the First Amendment is not absolute. No amendment is absolute," Schumer said on the Senate floor.

"You can’t scream ‘fire’ falsely in a crowded theater. We have libel laws. We have anti-pornography laws. All of those are limits on the First Amendment," he said. "Well, what could be more important than the wellspring of our democracy? And certain limits on First Amendment rights that if left unfettered, destroy the equality — any semblance of equality in our democracy — of course would be allowed by the Constitution.

"And the new theorists on the Supreme Court who don’t believe that, I’m not sure where their motivation comes from, but they’re just so wrong. They’re just so wrong," he continued.

The Disclose Act, which would not have gone into effect until January, would have required any organization that spends $10,000 or more during an election cycle to file a report within 24 hours identifying any donors who gave $10,000 or more. Current election law requires super PACS to make periodic reports to the Federal Election Commission, but not-for-profit groups, including social welfare organizations, labor unions and trade groups, generally do not have to reveal the sources of election-related spending.

Democrats have been pushing for more disclosure since the Supreme Court's 5-4 ruling in the 2010 Citizens United case that overturned a decades-old law barring corporations, unions and other organizations from spending on advertising and other forms of political activity.

But Republicans, like Senate Minority Leader Mitch McConnell, R-Ky., accused Democrats of wasting time on bills "they know won't pass but which give them a chance to make a fuss about a problem that doesn't exist and blow a kiss to the unions for good measure."

The Associated Press contributed to this report.