There are lots of complicated explanations for why the Democrats couldn’t pass the big infrastructure bill, and one simple reason:

Sheer political overreach.

Joe Biden isn’t the first president to fall into this trap, but it’s still rather stunning given his 44 years of experience as a senator and VP.

He just asked for way too much spending, far more than the system was capable of swallowing.

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And the Democrat who campaigned as a moderate—which is essentially how he beat Bernie Sanders—is now pushing most of the Bernie agenda, which, not surprisingly, is politically toxic for middle-of-the-road lawmakers.

The narrow-mindedness of the progressive Democrats and their media allies is rather breathtaking. They are blaming Joe Manchin and especially Kyrsten Sinema, who has been trashed on MSNBC, mocked by "SNL" and John Oliver, and described in a Maureen Dowd column as the Greta Garbo of Capitol Hill. A liberal activist even followed Sinema into a bathroom in Phoenix to harangue her. Without Sinema and Manchin, Biden’s party wouldn’t have 50 Senate seats.

The president himself, asked by reporters yesterday why someone with his experience couldn’t win a House vote on his agenda, blamed it on "two people"—as if they were political opponents.

Biden mentioned that he opposed Medicare for All during the campaign and that this bill isn’t by "Bernie or AOC," isn’t "somebody else’s legislation," but that "I wrote it." That suggests a defensiveness about all the coverage that he’s gone too far left.

Of course, Nancy Pelosi didn’t have the votes on the $1.2-trillion infrastructure bill because the progressives are holding it hostage to get their $3.5-trillion Democratic wish list bill—which was in fact largely written by Bernie Sanders.

As a matter of tactics, it’s hard to see why a president who won by 7 million votes felt the need to placate his left wing with such a gargantuan amount of spending. Or allowed that top-line figure to become the focal point, as opposed to branding it as a health care bill or climate bill or help-the-kids bill.

Biden may have thought he’d give himself room to come down—but that much room? When the combination of both measures, plus the Covid relief law, nearly equals the entire federal budget?

The media are also acting like that 3.5 figure is the holy grail. A Washington Post piece over the weekend was headlined "White House Confronts Grueling Choices As It Debates Major Cuts to Biden Economic Plan." Now spending anything less than 3 and a half trillion dollars is a cutback—and a painful one at that?

The world would look very different if Biden had forced his party to take the win on infrastructure—a remarkable achievement, actually—and then battle for these additional programs.

President Joe Biden delivers remarks on the debt ceiling during an event in the State Dining Room of the White House, Monday, Oct. 4, 2021, in Washington. (AP Photo/Evan Vucci)  (Evan Vucci)

From a broader perspective, the problem may be that liberals have become too successful—so much so that they are cocky and overconfident in their ability to remake the world.

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One year ago, they didn’t control the White House or Senate and were nervous about beating Donald Trump. Now they feel entitled to break the bank with an FDR-style agenda, only with razor-thin majorities?

George W. Bush couldn’t privatize Social Security. Barack Obama couldn’t pass gun control. Donald Trump couldn’t repeal ObamaCare. They all bumped up against the limits of political reality.

In his New York Times column, Ross Douthat argues that Democratic liberals back in 2003 would have been thrilled with the way the culture has changed today.

One, Bush’s Iraq-era military interventionism is a distant memory (and Trump had a whole lot to do with that).

Two, the agenda of "values voters" is no longer ascendant. Bush ran in 2004 on a constitutional amendment to ban same-sex marriage, and now, courtesy of a Supreme Court with a conservative majority, it’s the settled law of the land.

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Three, the push for smaller government—as exemplified by the Tea Party revolt and Paul Ryan’s drive to reform Medicare and Medicaid—has hit a dead end.

Instead, says Douthat, we have "an unprecedented experiment in social spending to carry the country through the pandemic, and a further spending surge under Biden — with Joe Manchin, the most rightward Senate Democrat on fiscal matters, standing to the left of where Obama stood 10 years ago."

And yet the left regularly delivers gloom-and-doom warnings, perhaps recognizing that the resurgence of the welfare state and individual rights is producing "a somewhat darker future than they thought."

Of course, liberals would counter that they’re battling a Republican Party in which a majority believe Biden stole the election.

Now all the infighting may prove to be a blip if Biden eventually forces his party into a compromise that would still add trillions to domestic programs. But at the moment, it looks like he allowed his most ardent left-wingers to push him into political quicksand.