As the prospect of Donald Trump’s defeat becomes more real, Republicans are assembling an explanation for what went wrong. It says that even if Trump overstated the degree to which the system is “rigged,” there was still lots of voter fraud; that the media first elevated Trump to the nomination then destroyed him in the general election; and perhaps most importantly, that Hillary Clinton was such a terrible candidate that if only they hadn’t been tricked and manipulated into nominating Trump, they would have won the White House.

Mike Pence would have beaten Clinton. Or Marco Rubio would have. Even Jeb Bush might have. Peggy Noonan writes that a “sane” version of Donald Trump “would have won in a landslide.” She then goes on to describe this imaginary candidate who is absolutely nothing like Donald Trump, but is instead a thoughtful, informed, inclusive candidate with well-thought-out positions and impeccable political instincts.

This is the real lesson of their lament: Though they’d never put it this way, the Republicans’ biggest mistake was that they failed to nominate, guess what, a politician. But this didn’t happen by accident. Instead, it was the logical end point of everything they’ve been telling their constituents for years.

Republicans set the stage for Trump not only by stoking Tea Party anger, but by convincing their constituents that the very idea of politics is repugnant, and only someone untainted by it could lead their party. And then they’re amazed when the political neophyte they nominated turns out to have no idea what he’s doing.

For the moment, let’s set aside the question of whether Republicans would really be winning with a different nominee (I think the race would be closer, but Democrats would still have the advantage). What this hypothetical alternative would bring is the skills, experience, and knowledge you gain by being active in politics, exactly what Trump lacks. He’d know how to run a proper campaign. He’d have a grasp of substantive policy issues, and know how to communicate Republican positions to voters in a persuasive way. He’d understand how not to alienate key groups of voters. He’d be in control of his emotions, able to give a speech or participate in a debate without damaging outbursts.

In other words, he’d be a politician. You may notice that no Republicans are saying this election would be a lock if only Ben Carson or Carly Fiorina had been their nominee.

Yet for years, Republicans have been running against “Washington,” an irredeemable Sodom of corruption and malfeasance. Anyone who wants to actually make government work is immediately suspect, an “insider” whose motives can only be nefarious. They look for “outsiders” who can tell voters, “Elect me because I’m not a politician, I’m a businessman.” Granted, there have been a few Democrats who have made that claim too, but Republicans are particularly attracted to it, despite the fact that it’s ludicrous on its face. If you hired a carpenter to build you a deck and you didn’t like the way it turned out, you wouldn’t say, “What we need to fix this deck is someone who’ll think outside the box. Like a computer programmer, or a librarian. Just as long as it’s not another carpenter.” No, if you were a rational person, you’d decide to get yourself a better carpenter.

There’s an old saying that Republicans claim government doesn’t work, and then when they actually get power, they set out to prove it. Sometimes it’s not so intentional; they do it in ways that seem reasonable at the time, but have the effect of making things much worse, all with the goal of taking the politics out of politics. For instance, after they took control of the House in the 2010 election, they banned “earmarks,” budget items targeted to specific members’ districts (it should be said that this was a move many Democrats supported at the time). Earmarks never made up more than a tiny portion of the federal budget, but they did on occasion produce less than worthy projects (you may remember the “Bridge to Nowhere“), and even some opportunities for corruption.

But what everyone discovered after they were eliminated was that earmarks were also a critical tool in greasing the wheels of legislation. Congressional leaders could say to a wavering member, “Support us on this spending bill, and we’ll throw in a new wing for that hospital in your district.” Most of the time the projects were perfectly useful, and the horse-trading enabled the process to keep moving. Without earmarks, leaders don’t have that carrot they can use to convince members not to gum up the works in order to make a symbolic stand against Washington.

Or consider term limits for Congress, which Donald Trump recently endorsed and which many Republicans favor. The idea is that if we just get rid of all the politicians and replace them with citizen legislators who serve for a couple of years and then go back to their farms and corner stores, “common sense” will reign and we’ll be able to solve all our problems. But it turns out that’s not what happens; instead, when term limits are instituted at the state level you get a bunch of clueless legislators who have no idea what they’re doing. In 2014, Governing magazine explained the many problems with term limits that have been documented in multiple studies.

Today, if you want to know why Washington doesn’t work, it’s not the insiders that are the problem. They’re not the ones refusing to move legislation, or shutting down the government, or threatening to default on the national debt. It’s the outsiders, the Republicans elected in 2010 and after who came to Washington hoping to burn the place down.

When you spend all your time denigrating not only “Washington” but everything about politics — complex legislation, compromises, deal-making, substantive expertise — and instead make ridiculous promises of revolutionary change that can be accomplished just by listening to your gut and doing some Founding Father cosplay, you set yourself up for failure. And in the most extreme case, you nominate Donald Trump for president.

So can Republicans actually understand this problem and do something to change it? As it is so often, the key force constraining the GOP from making the necessary change is its own constituents, who have bought what Republican leaders sold them. After hearing this message for so long, they’ve been convinced to see politics this way, and it’s going to take a long and difficult effort to persuade them otherwise. But Republicans had better try,  unless they want their party to keep getting hijacked by “outsiders” who bumble their way to defeat and destruction.