(CNN) -- Senate Republicans again Tuesday blocked Democratic legislation that would require greater transparency into who is behind much of the secretive, often negative campaign advertising filling the airwaves this election season.
Supporters of the DISCLOSE Act mustered 53 votes in an effort to advance the bill, but fell short of the 60 needed to break a GOP filibuster.
What follows is the statement prepared by Senate Majority Leader Harry Reid, D-Nevada, for delivery Tuesday on the Senate floor, provided by his press office:
"The corrosive effect of money on American politics is not a product of the 21st century.
More than 100 years ago, moneyed special interests had already tested the integrity of this country's political system.
In 1899, Copper billionaire William Clark was elected to the United States Senate by the Montana state legislature. The contest was considered so blatantly swayed by bribery, the Senate refused to seat him.
Clark famously responded: "I never bought a man who wasn't for sale."
Incensed Montana voters went on to pass the Corrupt Practices Act via referendum.
Less than a decade later, Republican President Theodore Roosevelt reigned in unlimited corporate giving to political candidates at the federal level as well.
This nation has a long history of curtailing the corrupting influence of money in politics.
But with its Citizens United decision, the United States Supreme Court erased a century of effort to protect the fairness and integrity of American elections.
That disastrous decision opened the door for big corporations, anonymous billionaires and foreign interests to secretly spend hundreds of millions of dollars influencing voters.
For anyone who dismisses this change as politics as usual, think again.
During this year's election, outside spending by GOP shell groups is expected to top $1 billion -- that's billion with a "B."
The names of these new front groups contain words like "freedom" and "prosperity."
But make no mistake -- there is nothing free about an election purchased by a handful of billionaires for their own self-interest.
Just one of these outside groups, backed by wealthy oil interests, has promised to spend $400 million on negative ads filled with half-truths and distortions of President Obama's record.
By comparison, during the 2008 election, Senator John McCain's presidential campaign spent $370 million -- total.
So this year one group's special interest money will dwarf the entire budget of the Republican nominee in the last presidential election.
Democrats -- and the majority of Americans -- believe these unlimited corporate and special-interest contributions should be outlawed.
But in a post-Citizens United world, the least we should do is require groups spending millions on political attack ads to disclose their largest donors.
We owe it to voters to let them judge for themselves the attacks -- and the motivations behind them.
The DISCLOSE Act would require political organizations of all stripes -- liberal and conservative alike -- to disclose donations in excess of $10,000 if they will be used for campaign purposes.
Safeguarding fair and transparent elections used to be an area where Democrats and Republicans could find common ground.
As far back as 1997, the Republican Leader said, "Disclosure is the best disinfectant."
In fact, 14 Republicans now serving in this body voted to support stronger disclosure laws in 2000.
Yet last night those 14 Republicans did an about-face. And every one of my Republican colleagues voted to block the DISCLOSE Act.
It is obvious Republicans' priority is to protect a handful of anonymous billionaires -- billionaires willing to contribute hundreds of millions of dollars to change the outcome of a close presidential contest.
But today they'll have an opportunity to reconsider that backwards priority and stand up for the average voter instead.
I hope they join Democrats as we work to ensure all Americans -- not just the wealthy few -- have an equal voice in the political process."