“If pro is the opposite of con, then progress is the opposite of Congress.”

That very old joke seems to remain fresh in the minds of Americans, because Congress, evenly split between Democratic control of the Senate and Republican control of the House, ranks at just 13.9 percent approval in the most recent Real Clear Politics average of major polls.

Nonetheless, history shows that 90-plus percent of members running for re-election this year will retain their seats, because that happens even in years when control of one or both chambers switches between the parties.

The advantages of incumbency (name recognition, ability to take credit for every federal spending project, continuous coverage in the media, numerous local offices, etc.) are simply too great for most challengers to overcome.

But seats will change, either by vacancies or by atypical upstarts overcoming incumbents’ advantages.

So The Hill, an online paper that covers Congress, reported Sept. 12 that Republicans have an “action plan” if they win both houses in November.

When I read the headline, I thought, “This is good news. While they won’t be able to override Obama’s vetoes, at least they can make him actively oppose things like privatizing health care, restoring adequate military funding, opening federal lands for oil drilling, building a fence along the Mexican border and many other things that are polling well with American voters.”

But then I read the story.

According to the paper, the GOP’s agenda includes “authorizing the long-delayed Keystone XL oil pipeline, approving ‘fast-track’ trade authority, rolling back (some) new Environmental Protection Agency regulations and repealing Obamacare’s unpopular tax on medical devices.”

That’s it? That tiny list of “initiatives” (if you can call them that), while worthwhile, is hardly a taste of what conservatives want their representatives to do.

Conservatives want President Barack Obama to have to veto truly substantial popular measures, and thus force the Democratic nominee in 2016 either to support those vetoes (thus opposing popular bills) or repudiate Obama, and put himself (or herself) at odds with the lame-duck president’s true believers.

But the GOP’s nothingburger agenda is what makes our politicians fully deserve their 13 percent approval rates.

Across the aisle, a stellar example of congressional perfidy occurred this month when Democratic senators (joined, sadly, by independent Sen. Angus King) almost unanimously tried to repeal the First Amendment.

They never had a chance of doing it, but that they felt confident enough to try is a shot across the bow for civil libertarians.

As the online Washington Free Beacon reported Sept. 12, a constitutional amendment sponsored by Sen. Tom Udall, D-N.M., ostensibly would overturn the Supreme Court’s Citizens United ruling, which allowed corporations and unions to contribute to political campaigns in the same way individuals do.

But it would do far more than that, allowing states and Congress to “regulate” all political advertising and ban whatever they didn’t like. Analysts say that if Democrats wanted to make ads for Republican candidates illegal, this amendment would permit it.

In a June 3 letter to Congress, the American Civil Liberties Union said the amendment would “break the Constitution” by being “deceptively complex,” “unnecessary,” “redundant of existing law,” “dangerous for liberties,” “vague,” “overbroad” and “exceedingly dangerous to democratic processes.” It marked “the first time the amendatory process has been used to directly limit specifically enumerated rights and freedoms.”

Still, the amendment garnered 54 votes in the Senate, none from Republicans (three Republicans and one Democrat didn’t vote). It needed 67 votes (two-thirds of the Senate) to go to the states, where approval from three-fourths of them, or 38, would be needed for it to take effect.

The amendment isn’t designed to drive big money out of politics. It is designed to drive conservative money out.

It exempts the media from regulation, but, the paper said, “the government would determine who or what ‘the media’ are. Certified institutions would become the few remaining outlets for free expression.”

In addition, “by endowing governments with the power to ban anonymous political giving, (it) would usher in an era of witch-hunts and public shaming, with the media using their new powers to condemn and malign and stigmatize and penalize the advocates of unfashionable causes.”

Who would that be? Well, it wasn’t liberal groups the IRS targeted for “special scrutiny” before the 2012 elections.

Who would be favored? As the paper noted, “The top three individual contributors to federal elections this cycle are Tom Steyer (net worth $1.7 billion), Michael Bloomberg ($34 billion) and Fred Eychaner (perhaps $1 billion). They are not Republicans.”

Though the amendment probably was designed primarily to spur donations from the party’s base, it still proves Democrats are willing to shred the Constitution to favor their interests.

Which is a good reason to hope they never get the opportunity to do so when it counts.

M.D. Harmon, a retired journalist and military officer, is a freelance writer and speaker. Email at: mdharmoncol@yahoo.com.