Recently, the Senate Judiciary Committee approved a joint resolution offered by Sen. Tom Udall proposing a new amendment to the U.S. Constitution.

The amendment would give Congress the power to regulate and place limits on political spending, not just from campaigns and SuperPACs, but any political spending.

Taking a loose interpretation of the language could give Congress broad censorship power over all forms of media.

It's the biggest communications power grab by the federal government since the Fairness Doctrine, only with far more potential to do harm.

The resolution, which has been cosponsored by 43 Democratic senators and two independents, is now eligible to be brought to the Senate floor by Senate Majority Leader Harry Reid, D-Nev., at any time.

Sen. Ted Cruz, R-Texas, has spoken out strongly against this idea, calling it an attempt to “repeal the First Amendment.”

In fact, the effect this amendment would have on free speech would be dramatic, and the potential for abuse is vast.

The insidious nature of the amendment lies in its brevity -- just one page -- in which Congress is granted broad new regulatory powers over political spending.

The amendment grants Congress the authority to limit “the amount of political funds that may be spent by, in support of, or in opposition to” political candidates.

What any of that means in practice is subject to a great deal of interpretation. What does it mean to spend money in support of a candidate?

Or to oppose one? Is writing a book about a candidate considered political spending? How about making a movie about one? How is Oliver Stone going to feel about this?

The proposal goes out of its way to exempt “the press” from political spending limits, but again, what is “the press” and who defines it?

The amendment would essentially give the administration the power to decide who can and who cannot criticize it, an eerie echo of President John Adams' infamous Alien and Sedition Acts more than 200 years ago.

The founding fathers anticipated these sorts of problems, which is why they made it extremely difficult to amend the Constitution.

Without a two-thirds majority in both houses and a three-fourths majority of the state legislatures, there's nothing Reid can do apart from put on a show and gin up support for vulnerable Democrats in November.

Still, the very attempt to change the Constitution in such a fundamental way is troubling. That there are 45 members of the U.S. Senate who think that free speech should not extend to the realm of politics proves how fragile our basic liberties are, and what a deep hole we’ve dug ourselves into.

The Supreme Court has, for now, ruled that campaign contributions qualify as protected political speech under the Constitution.

If the composition of the court changes (which it is likely to if Republicans don't win the White House in 2016), the very first among our freedoms can be taken away from us with the stroke of a pen.

Udall’s proposal is not the first time Democrats have tried to stifle political speech, nor will it be the last. The obvious question is why? Don’t they have as much to lose from censorship as anyone else?

Democrats want this amendment because it hurts the grassroots the most, and the grassroots are no longer on their side.

If the pattern of Obamacare is any guide, you can bet that K Street lobbyists, labor unions and special interest groups would secure exemptions, while the limits fall most heavily on ordinary people attempting to organize in favor of better representation.

They don't want any more Dave Brats. They don't want any more Ted Cruzes. They don't want any more Mike Lees.

The grassroots are gradually taking over the political process, and the Democrat establishment knows it. That’s why they’re trying to shut us down in any way possible, and that’s why we have to fight back, each and every time.

Matt Kibbe is president of FreedomWorks for America and author of the New York Times bestseller, "Don't Hurt People and Don't Take Their Stuff."