The GOP's intra-party war continues, with Donald Trump blaming Senate Majority Leader Mitch McConnell for the failure of the Obamacare repeal effort.

On Twitter, Trump wrote, "Senator Mitch McConnell said I had 'excessive expectations,' but I don't think so. After 7 years of hearing Repeal & Replace, why not done?"

It's a fair question. Part of the answer is that elected Republicans failed for years to seriously engage with the question of how to replace the health care law they campaigned so adamantly against. But it's also an exercise in calculated blame shifting, one that demonstrates how little the president understands about the policy process. In other words, it's the entire party's fault.

Trump's tweet was a response to McConnell's recent statement suggesting that the president may not be realistic about what Congress can do. "Our new president, of course, has not been in this line of work before," McConnell said this week. "And I think he had excessive expectations about how quickly things happen in the democratic process."

Senator Mitch McConnell said I had "excessive expectations," but I don't think so. After 7 years of hearing Repeal & Replace, why not done? — Donald J. Trump (@realDonaldTrump) August 9, 2017

Trump's inexperience is a factor here. But the outsider president's expectations were set in large part by seven years of Republican promises to repeal and replace the health care law. And throughout that time, Republicans were never really serious about developing a replacement plan that could pass.

Back in 2013, when Obamacare's exchanges went online, and immediately crashed, it was clear that many Republicans were simply not interested in productive health policy improvements. Instead, they viewed the struggles of the health care law strictly as a political cudgel to wield against political opponents.

To be clear: I am not saying that there were literally zero Republican health care policy proposals. There were any number of white papers and policy frameworks and even a fully written piece of legislation or two. But there was very little effort to sell these plans to either the broader public or to Republican lawmakers, and to create the political conditions under which they were likely to both pass and be successful. What Republicans lacked was a shared vision—a theory of the case and how best to address it.

These efforts take significant time and energy. Democrats and their allies on the left spent nearly two decades working through ideas and building broad consensus after the failure of President Bill Clinton's health care plan in the early 1990s. Republicans didn't mount a similar effort. This was a widespread institutional failure driven by a combination of policy disinterest and political cynicism.

Indeed, former House Majority Leader Eric Cantor basically admitted as much in a recent interview with Washingtonian, in which he says that Republicans knowingly overpromised on what was possible in terms of rolling back President Obama's legislative achievements.

This is where Trump's experience comes into play. Trump, an outsider with no history with the Republican politics, was not in on the plot. He did not know that it was, essentially, a ruse.

Thus, when it came time to act, Republicans did not have a shared vision and a plan to advance it. Under a more conventional Republican president, the GOP-controlled Congress might have managed to pass something—quite possibly a very flawed something—anyway. The president typically plays a key role in both unifying his own party and in selling the bill to the public. Obama, for example, helped smooth over lingering differences amongst Democrats, and made it a priority to sell his bill to the public, in great length and detail.

But Trump, a neophyte who has demonstrated no in-depth understanding of health care policy or the political dynamics that surround, and who did not bother to educate himself on those issues, could not and did not play this role. This is especially critical when it comes to health care, where the policy is knotty and interconnected, and the politics are deeply intertwined with the complexities of the policy choices.

When Trump and his aides did weigh in, they set public expectations for broad comprehensive coverage that no Republican bill was ever going to match. He also promised in January that the administration had its own plan nearly finished, which clearly was not true.

Mitch, get back to work and put Repeal & Replace, Tax Reform & Cuts and a great Infrastructure Bill on my desk for signing. You can do it! — Donald J. Trump (@realDonaldTrump) August 10, 2017

It didn't help that Trump's victory caught congressional Republicans by surprise. "I didn't expect Donald Trump to win, I think most of my colleagues didn't, so we didn't expect to be in this situation," Sen. Pat Toomey (R-Pennsylvania) said last month when asked about his party's difficulty passing health care legislation.

With Congress anxious and unprepared, and the president unable to manage the process, there was no one left to design a plan that could unite the party, and no one left to sell the public on the merits of a different system. It remains remarkable how little effort nationally elected Republicans spent making the case for the specific virtues of their legislative ideas. It gave the impression—which in some cases was true—that Republicans themselves did not much like their plans.

In turn, Obamacare became more popular. The Republican legislation was the least popular major bill in decades.

The failure, then, was party wide. Republicans in Congress weren't prepared to repeal and replace Obamacare, and may never have intended to. Trump managed to win the GOP nomination and then the presidency without figuring this out. And as president, he was particularly ill-suited to helping Republicans work through their own divisions and hang-ups. If anything, it's amazing that Republicans came as close to passing something as they did. Expecting anything from a political party this at war with itself is probably excessive.

And now Trump is merely continuing the cycle of dysfunction, using the failure of the GOP health care effort to stoke tensions within his own party that are politically convenient for him, but unlikely to advance any policy goals. If you want to understand the GOP failure to advance a policy agenda, if you want to know about Obamacare repeal and "why not done," Trump's own tweet is as good a place as any to start.