Obamacare open enrollment starts on November 1, and President Trump is using Twitter to blame Democrats for premium increases, and promising yet again to repeal the health care law.

As usual, the ObamaCare premiums will be up (the Dems own it), but we will Repeal & Replace and have great Healthcare soon after Tax Cuts! — Donald J. Trump (@realDonaldTrump) October 29, 2017

Do Democrats “own” the rising rates, though? Not if you ask the health insurers and policy experts who have set and study those premiums.

As Vox documented in great detail, premiums on the law’s marketplaces were expected to stabilize this year, as insurers finally adjusted to the customers who were buying coverage. Single-digit rate increases, on average, were anticipated. It wasn’t perfect, but the law was reaching an equilibrium.

But then Trump intervened. He sowed uncertainty about whether the law’s individual mandate would be enforced. He cut funding for advertising and enrollment outreach.

Then the president stopped key cost-sharing payments to health insurers, which compensate companies for offering discounts on out-of-pocket costs to their lower-income customers. Insurers had warned they would hike rates as a result.

As Vox reported earlier, health plans and actuaries say Trump’s actions have raised premiums by at least 25 percent and as much as 45 percent from what they otherwise would have been.

Millions of Americans who receive federal assistance to buy insurance will be insulated from the rising rates. But the law’s middle-class customers who make too much money to receive that aid — many of them Republicans — will be on the hook.

No matter what Trump tweets.