Friday was arguably the worst day for Joe Biden’s presidency so far. And it could be the death knell for the Build Back Better bill’s lurch toward big-government socialism.

First, the Labor Department reported inflation is now running at just under 7 percent over the last year. Prices were rising at a 2 percent annual pace when Donald Trump left office in January and then 5 percent this summer and now this.

Notice a trend?

And, sorry, no, this inflation isn’t “transitory.” And, no, CNN, it isn’t “good for you” — or me, or anyone. Meat prices are up 20 to 25 percent, car prices up 29 percent, and a fill-up at the gas station costs $20 more than a year ago.

Joe Biden and his media flacks rushed to the TV cameras in full damage-control mode on Friday to assure Americans that passing the BBB plan would reduce inflation. One wonders whether these folks would pass a lie-detector test. Americans aren’t buying it. Polls show more than half of voters blame Biden and runaway spending for inflation. 

But then a few hours later came the second body blow to the Biden agenda. The Congressional Budget Office released a report that examined the true cost of the Biden BBB plan — minus the accounting gimmicks. The results were devastating: twice as high as previously reported and closer to $5 trillion in spending over the next decade. Instead of “paying for itself,” as Biden claims, the deficit could skyrocket by almost $3 trillion more if Congress passes BBB. 

Whoops! This is a bit more than a rounding error. If a private CEO tried to get away with these accounting scams, they’d be put in jail.

West Virginia’s Democratic Sen. Joe Manchin is now admitting the obvious: He’s worried that another multitrillion-dollar spending bill steamrolling through this Democratic Congress will make the inflation contagion worse. 

He wants a “strategic pause” for a social-welfare/climate-change bill that he now calls bad for the country — and especially bad for West Virginia, a gas and coal state.

I’d rather put a dagger through the heart of this oinker spending bill altogether. As even Obama economist Jason Furman has pointed out, inflation is not a global phenomenon right now, as evidenced by the much lower price increases in Europe. 

The inflation contagion is a made-in-Washington crisis. If the Washington spending spree doesn’t end soon, the inflation will continue to climb and put America at risk of a financial crisis and a gut-wrenching recession.

And, if that happens, Joe, the first job that will be lost will be yours.

Stephen Moore is an economist at Freedom Works who served as a member of President Donald Trump’s Economic Recovery Task Force.