I’ve said this before, but in light of Mitt Romney’s economic speech today, it bears repeating: Virtually his entire case against Obama’s economic record rests on the assumption that the American people have developed a case of mass amnesia about the depth and severity of the economic crisis the President inherited.

A few months ago, Romney liked to claim that Obama made the economy “worse.” But the good economic news forced Romney to revise that argument, and he took to claiming that, yes, okay, the economy is getting better, but only in spite of Obama’s policies, which are slowing down the natural recovery.

Today Romney upped the ante yet again, offering still another explanation for why Obama should be denied a second term, even though the economy is recovering: It’s all about freedom! From the prepared remarks:

The Obama administration’s assault on our economic freedom is the principal reason why the recovery has been so tepid — why it couldn’t meet their projections, let alone our expectations. If we don’t change course now, this assault on freedom could damage our economy and the well-being of American families for decades to come...

The proof is in this weak recovery. This administration thinks our economy is struggling because the stimulus was too small. The truth is we’re struggling because our government is too big.

Relatedly, this morning, Romney said: “The economy always comes back after a recession, of course. There’s never been one that we didn’t recover from. The problem is this one has been deeper than it needed to be and a slower recovery than it should have been, by virtue of the policies of this president.”

The common thread here is obvious, and it’s important. The pace of this recovery, according to Romney, is sluggish compared to that of previous ones — proving that Obama’s policies, or his “assault on freedom,” are the reason why. Missing from this telling, of course, is the most important reason this recovery is different from previous ones: It came after the worst financial crisis since the Great Depression.

Romney’s argument that the recovery’s pace would otherwise have been normal if not for Obama’s polices rests on a bet that the American people will forget about this, or won’t factor it into their decision this fall. Perhaps some enterprising reporter will ask Romney the obvious follow-up questions: What would you have done as president in early 2009? Is it really your contention that the economy would have recovered at a typical pace from the worst financial crisis since the 1930s if government had done nothing at all?