President Trump has shown his hand. Now we know.

Trump told Fox Business on Aug. 13 that he opposes emergency funding for the US Post Office because it would help the service deliver more mail-in ballots in November. “They need that money in order to make the post office work, so it can take all of these millions and millions of ballots,” Trump said. “But if they don’t get those two items, that means you can’t have universal mail-in voting, because they’re not equipped to have it.”

This, we can now see, is a major reason Congress can’t pass another stimulus bill to help businesses and workers reeling from the coronavirus recession. The “two items” Trump referred to are additional funding streams Democrats want as part of the next stimulus bill: $25 billion to plug ongoing financial holes at the postal service, and $3.6 billion to help states fund a surge of mail-in voting. Republicans who control the Senate oppose that funding, and Trump has now indicated why.

Trump thinks mail-in voting will help Democrats more than Republicans. In March, Trump told Fox News that with expanded mail-in voting, “you’d never have a Republican elected in this country again.” There’s no evidence that’s true. Many states have liberal mail-in voting rules that cause no apparent problems, including Republican-controlled states such as Iowa, Montana, Ohio and Utah. Yet Trump seems convinced, without proof.

The $28.5 billion Democrats want for postal-related funding is a blip in a bill that could easily total $1.5 trillion in spending, or more. So Republican objections based on the dollar amount alone don’t really make sense. If Trump thinks that additional postal funding endangers his hold on power, however, it would explain why Republicans would be willing to hold up a crucial bill for a relatively small provision.

Still, it’s probably counterproductive for Trump to starve the postal service and spell out his plan. Democrats led by House Speaker Nancy Pelosi and presidential hopeful Joe Biden can now accuse Trump of standing in the way of vital aid for struggling workers and businesses because he’s trying to rig the mail to aid his reelection odds. Seventy percent of Americans support voting by mail, including 87% of Democrats and 49% of Republicans, according to Pew Research. Trump needs the votes of moderate Republicans and many Independents to win in November, and he’s not helping himself by attacking postal voting.

Democrats can’t back down now

Trump’s revelation also seems certain to stiffen support for the new postal funding among Democrats. In March, when Congress passed the first large stimulus bill, Democrats caved on the $25 billion in postal funding they wanted, in order to ink a fast deal with Republicans. But now they can’t cave, without giving Trump an obvious win. Trump’s open hostility to the postal service now gives Democrats a cause they can’t back down from, like a martyr who infuses an army with a rallying cry.