WASHINGTON, DC - MARCH 11: The American Flag flies over the Senate side of the U.S. Capitol, as Senate Democrats speak nonstop on the chamber floor about climate change on March 11, 2014 in Washington, DC. The self-titled 'climate caucus', a group of 26 senators working with a parallel House caucus, started speaking in the evening on March 10th and plan to continue until the morning of March 11th in an effort to elevate the issue of global warming. (Photo by Mark Wilson/Getty Images)

This week Senate Republicans blocked consideration of a constitutional amendment that would have overturned the Supreme Court's disastrous Citizens United decision and allowed us to crack down on the flood of corporate money in politics. Every single Republican senator voted against it.

Let's look at what they voted to uphold. Citizens United is a disgrace of a decision, holding that corporate money is corporate speech, and entitled to the same First Amendment protection as human speech. As a result, corporations now can spend unlimited amounts of money to influence our elections -- often in secret, without any public disclosure.

Simply put, the decision was factually erroneous and legally misguided. We need to get rid of it, and the public strongly agrees. One poll released earlier this year showed that 80 percent of Americans opposed the Citizens United decision. So how did Republicans justify their defense of this historically bad decision which the public overwhelmingly dislikes? By pretending that the debate was actually about something else, and by cloaking themselves in the rhetorical protection of the Constitution.

Senator Ted Cruz summed up the Republican strategy when he took to the Senate floor to accuse supporters of the proposal of attempting to "repeal the free speech provisions of the First Amendment." Conservative columnist George Will echoed the same argument, writing that supporters had "tried to radically shrink First Amendment protection of political speech."

Now, that argument may make for a good sound bite, but it is completely wrong. The question is whether the First Amendment protects unlimited corporate spending on elections. It never did, until Citizens United. To suggest, when we are debating whether the First Amendment properly applies to corporate influence in politics, that the proposal's supporters are repealing or shrinking the First Amendment, is to presume the merits of one's own case, not to address the argument.

Senate Democrats and the vast majority of the American public believe that freedom of speech protections were never intended to allow unlimited corporate spending on elections. Under a proper reading of the Constitution, they still don't. As Justice Stevens wrote in dissent, the Citizens United decision represented "a rejection of the common sense of the American people, who have recognized a need to prevent corporations from undermining self-government since the founding, and who have fought against the distinctive corrupting potential of corporate electioneering since the days of Theodore Roosevelt."

If Republicans want to defend the rights of corporations and billionaires to spend unlimited, secret money in campaigns, then they should say so. But they do not get a free pass to defend unlimited, secret political spending by sidestepping the question and pretending that Democrats are attacking our nation's First Amendment. The American public won't be fooled so easily.