Republicans, who are now not-so-subtly telling Donald Trump to knock it off when it comes to alleging that the 2016 election is rigged, aren't just pushing back on the GOP presidential nominee — they're battling their own party's long-standing claims about voter fraud and the “liberal media.”

Those claims laid the groundwork for what Trump is arguing today and make it that much harder to fight his ideas.

Trump appears to be setting up his rationale for not actually conceding the election, instead arguing that his loss was a combination of a media conspiracy and voter fraud.

At a debate Monday for his reelection campaign, Sen. Marco Rubio (R-Fla.) said Trump should stop it and that “this election is not being rigged.”

“I'm going to explain to you why it's not being rigged in Florida, and why I hope he stops saying that — why he should stop saying that,” Rubio said. “We have 67 counties in the state, each of which conduct their own elections. I promise you there is not a 67-county conspiracy to rig this election. Second, the governor of the state of Florida is a Republican, who appoints the people that run the division of elections. Third, there's no evidence behind any of this.”

Sen. Patrick J. Toomey (R-Pa.), who also hails from a key battleground state and is running for reelection, also repudiated Trump on Monday.

“Our elections may not always be completely perfect, but they are legitimate, they have integrity, and everyone needs to respect the outcome,” Toomey said.

Even Ohio Secretary of State Jon Husted (R), who is no friend of Democrats and has clashed with them repeatedly on voting issues, on Monday called Trump's rhetoric “irresponsible.”

“I am in charge of elections in Ohio, and they are not going to be rigged. I'll make sure of it,” Husted said during multiple CNN interviews on the topic. “Our institutions, like our election system, is one of the bedrocks of American democracy. We should not question it or the legitimacy of it. It works very well. In places like Ohio, we make it easy to vote and hard to cheat.”

A big problem for Republicans in all of this, though, is that they are fighting against the very same perceptions they have spent years promoting.

As Republicans have expanded voter ID laws to dozens of states across the country in recent years, the chief justification has been to combat voter fraud. Democrats have responded by pointing out just how few demonstrated cases of actual voter fraud there are (even fewer of which would be affected by voter ID laws), but Republicans have pressed forward, suggesting it's a big enough problem that it requires legislation.

The GOP's platform in 2012 included language supporting voter ID “to prevent election fraud, particularly with regard to registration and absentee ballots.”

Then-Texas Attorney General Greg Abbott (R), who is now governor, said in 2013: “Anyone who thinks there isn’t cheating going on at the ballot box is wrong.”

The conservative Heritage Foundation back in 2015 even put out a list of cases of alleged voter fraud to prove that it's a real problem.

As I wrote back in August — even as Trump had only really begun making his claims about a rigged election — all of this has led to Republican voters to believe pretty strongly that large-scale voter fraud does exist:

A Monmouth poll on the eve of the 2012 election showed that 51 percent of Republicans believed voter fraud to be a “major problem” in the United States. Similarly, a Washington Post-ABC News poll in July 2012 showed that 57 percent of Republicans thought voter fraud was a major problem.
Those are pretty general sentiments, but a Marquette Law School poll in Wisconsin in 2014 broke it down a little more (albeit only among Wisconsinites). Given a choice between how many votes were affected by at least one type of voter fraud, 54 percent of Republicans picked the largest option, saying at least one kind of fraud affected a few thousand votes or more in each election in that state. And 41 percent of independents agreed.

Now it's Republicans pressing the case of just how little actual voter fraud there is.

Here's why Trump's "rigged" claims just don't hold up (Peter Stevenson/The Washington Post)

And when it comes to the other half of Trump's argument — that the media is complicit and trying to bring him down — the GOP has also been fomenting a movement that it's now trying to tamp down. Trust in the media has declined significantly in recent years and decades, and most of that has been on the Republican side of the ledger. Ragging on the “liberal media” has proven both a very successful political strategy and business model, as conservative media outlets have sprung up in response to a demand for a different perspective.

Republicans would certainly argue that the media is getting what is deserved — and that's a valid topic of debate — but that doesn't change how they have been arguing for years and years that the media is not to be trusted. Trump's argument today is merely taking that idea to its logical extreme.

These Republicans have good reason to want to make sure people have confidence in the results of the election. Many of their own jobs depend on it, after all.

But they've done such a great job pressing claims of voter fraud and a biased media that many of them aren't just pushing back against Trump but, in a very real sense, against themselves.