A Democratic-led constitutional amendment to overturn Citizens United and subsequent rulings loosening restrictions on money in politics moved forward in the Senate on Monday evening.

The procedural vote was 79 in favor, 18 against.

The vote means the Senate can begin debate on the measure. But it is highly unlikely to ultimately pass the chamber as it faces fierce Republican opposition. It would need to clear another 60-vote threshold in order to end debate and come to a final vote. And that final vote would require the support of two-thirds of senators to succeed.

The measure, proposed by Sen. Tom Udall (D-NM), would restore the legal right of Congress to establish campaign spending limits. Approved by committee on a party line basis in July, it is one of several pre-election votes Senate Democrats are planning in an attempt to highlight the contrast between the two parties before Americans head to the polls.

Don Stewart, a spokesman for Senate Minority Leader Mitch McConnell (R-KY), said Republicans are happy to debate the measure, but “to be clear, there is zero support on our side for rewriting the First Amendment to restrict free speech.”

Democrats chose to spotlight the issue because the public is on their side. Most Americans oppose the Supreme Court’s 5-4 ruling in 2010, which wiped out limits on independent expenditures aimed at influencing elections, thereby giving rise to super PACs. Earlier this year, the same five justices ruled to further loosen campaign finance restrictions on aggregate spending by an individual to political candidates and committees in a given cycle.

In both cases, all five Republican-appointed justices voted to remove restrictions, while all four Democratic-appointed justices voted to uphold them.

McConnell, an ardent opponent of campaign finance restrictions, wrote an opinion piece for Politico magazine ahead of the vote bashing “the Democrats’ assault on free speech,” a line of attack also used by Sen. Ted Cruz (R-TX).

Progressive activists have been aggressively campaigning for the measure, viewing it as a long-term project. Adam Green, co-founder of the Progressive Change Campaign Committee, argued that the issue would help Democrats “excite voters this November.”