Topeka ? U.S. Sen. Pat Roberts last week voted against a proposed constitutional amendment that would limit campaign expenditures by corporations. But Greg Orman, his independent challenger in this year’s election, said he would support such an amendment.

Roberts was among 42 Republican senators who voted Thursday against closing debate on Senate Joint Resolution 19, a constitutional amendment that would reverse the U.S. Supreme Court ruling known as “Citizens United.”

The court said in that case that limits on independent expenditures by corporations and other groups violate their First Amendment rights to free speech.

“Our founding fathers knew that those in power would be inclined to retain it and, unless constrained, would use their power to punish those who would seek to challenge them or remove them from office,” Roberts said in a speech to the Senate Sept. 8. “The First Amendment denies us that power. It explicitly prohibits this Congress from passing laws that restrict the speech of the American people. With this amendment, the majority wants to try to remove that prohibition. They want to grant themselves the power to control speech — to silence their opposition.”

Orman, however, said he would support such an amendment as part of a broader package of campaign finance reform measures, including stricter limits on contributions from political action committees.

“Current campaign finance laws are a perfect example of how both parties are focused on their personal or partisan benefit instead of the American public,” Orman said in a statement released Monday. “The lack of transparency allowed under Citizens United benefits Washington’s broken system at the expense of an informed electorate, and even more alarming is that the decision opens up the door for significant foreign influence in U.S. elections because donations can be made through any U.S. corporation.”

The Citizens United case involved a conservative political group that wanted to air a film during the 2008 election cycle that was critical of Hillary Clinton, who was then a U.S. senator from New York seeking the Democratic presidential nomination. The group also sought to buy advertising time to promote the movie, and to distribute it through video-on-demand cable services.

But the Federal Election Commission said that would have violated the campaign finance law in place at the time, a law known as the McCain-Feingold Act which prohibited corporations and labor unions from making direct or independent expenditures in support or opposition to identifiable candidates.

On appeal, the U.S. Supreme Court ruled against the FEC, in favor of Citizens United, saying among other things that corporations are protected by the First Amendment’s right to free speech.

The vote to end debate on the amendment failed on a straight party-line vote: 54 Democrats voted yes, while 42 Republicans, including both senators from Kansas, voted no. Three Republicans and one Democrat did not vote.

Also voting no was Sen. John McCain, R-Ariz., one of the senators after whom the McCain-Feingold Act was named.

A constitutional amendment requires a two-thirds majority vote in both chambers of Congress and ratification by at least two-thirds of the states.