It’s been obvious for years that while Democrats claim to fear and loathe Donald Trump, they really can’t live without him. They need him around, they want him around, because they think he’s their ticket to remain in power.

Any doubt about that proposition vanished with President Biden’s Thursday night speech that had a single political purpose: Elevating Mr. Trump to the center of the fall campaign. Forget all the high-minded talk about saving democracy, which is hardly in danger in a midterm election in which Mr. Trump isn’t even on the ballot. Democrats want to pretend the former President is on the ballot to campaign against as the great Democratic foil.

That’s why Mr. Biden has so pointedly goaded Mr. Trump and his followers with the “MAGA Republican” label. His escalating rhetoric is intended to smear the GOP as under Mr. Trump’s sway and “semi-fascist.” If voters believe the stakes in November are the future of democracy, the autumn debate will shift from inflation, rising crime and woke ideology. More Democrats might vote, and the party might hold Congress.

All of this is deeply cynical and divisive. It contradicts Mr. Biden’s pledge, during the 2020 campaign and in his inaugural address, that he would unite the country. He repeated that claim of “unity” on Thursday but by now it is a throwaway line.

Even as we write this, his own party is running ads in New Hampshire to support the most MAGA Republican in the GOP Senate primary. A group allied with Senate GOP leader Mitch McConnell is supporting the other main GOP candidate. In his broadside, Mr. Biden is maligning half the country and the 70 million Americans who voted for Mr. Trump.

It’s possible this will work for Democrats in November, especially if Mr. Trump keeps taking Mr. Biden’s bait. Mr. Trump did precisely that on Thursday night with a typically ad hominem rant in response to the speech, which is exactly what Democrats want.

His regulators stretch the law beyond previous understanding to impose more control over the private economy. And that’s before they get the votes to break the Senate filibuster, add new U.S. states, override 50 state voting laws, and pack the Supreme Court. Mr. Biden has become his foe’s polarizing mirror image. It is exactly what he promised as a candidate he wouldn’t do.

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