Kiss Pennsylvania goodbye, and adios to Texas and Ohio too. At the end of last night’s debate, Joe Biden had begun to show signs that he was having trouble keeping up. This, however, was a massive unforced error that suddenly corroborated everything Donald Trump had warned about the Biden-Harris ticket and its environmental extremism.

Trump basically pushes Biden into admitting that he’d “transition from the oil industry” in his presidency, after months of double-talk around energy production:

Biden had gotten less coherent on energy policy as the debate wore on. At first, he denied that he ever opposed fracking, which is a flat-out lie that Trump himself exposed immediately after the debate. Biden then backed down to say that he only opposed fracking on federal land, which is also untrue but it concedes a lot of ground, literally speaking. Most of the oil- and gas-rich fields have to get accessed on federal land, thanks to decades of seizure of that territory from the states, which makes that a distinction without a difference.

This, however, is even worse, especially since Biden in the same answer pledged to bring us to “zero emissions” by 2025. The US has finally become a net exporter of energy by unleashing production through fracking and greater access to federal land. That production level allows prices to remain low, which is an absolute necessity for any economic recovery. Ending fracking and drilling on federal land will make us dependent on imports once again and to the price shocks that result from conflict abroad. The nation experienced a few such shocks during the Obama administration, when both Barack Obama and Joe Biden assured us — falsely — that we couldn’t drill our way to energy independence. The Trump administration quickly showed that we can, and that we did.

Biden’s pledge, if fulfilled, would have a number of secondary effects, and not just to the economy. Our energy independence has made us much less tied to foreign producers, which in turn gives us much more flexibility in foreign policy. A move to destroy American energy production would benefit Russia and Iran tremendously, making their exports much more valuable on the open and black markets. It would reduce our leverage even among allies like Saudi Arabia and Iraq, and recreate more problems in dealing with the collapsed Venezuelan regime. All of those effects make the risk of military conflicts go up substantially.

So for a number of reasons, “this is a big statement,” as Trump said and Biden echoed. It’s a big mistake, and not just for Biden’s prospects either. This will hurt down-ballot Democrats in oil-producing swing states like Pennsylvania and Ohio, and even more in Texas, where Democrats entertained fantasies of turning the state blue. Expect this answer to get hammered over and over again in the final ten days of the campaign.