WASHINGTON — President Donald Trump, a salesman so good that he sold his personal brand all the way to the White House, may finally have met something he can't sell: "Democrat Shutdown."

As the federal government careened toward a partial shutdown Friday night over Trump's demand for $5 billion to build a border wall, which does not have enough votes in the Senate to pass, Trump looked for someone to blame. But he quickly ran into trouble, not least because he'd already told the country he would take the blame himself.

"Senator Mitch McConnell should fight for the Wall and Border Security as hard as he fought for anything. He will need Democrat votes, but as shown in the House, good things happen. If enough Dems don't vote, it will be a Democrat Shutdown!" Trump tweeted on Friday morning.

A few minutes later, Trump tweeted, "Shutdown today if Democrats do not vote for Border Security!"

This message, that Democrats should be blamed for the government shutting down if they failed to approve funding for Trump's border wall, is not a new one for the president.

Trump said almost exactly the same thing 10 months ago, the last time the federal government was on the brink of a shutdown over the same border wall impasse.

"I'd love to see a shutdown if we don't get this stuff taken care of," Trump said at a White House meeting on the eve of a shutdown in February. "If we have to shut it down because the Democrats don't want safety, then shut it down."

That time the shutdown only lasted nine hours, so there wasn't very much blame to go around.

More importantly, Trump had been consistently blaming Democrats throughout the process, so it was more a case of two dueling messages — one coming from the White House and congressional Republicans, and one from the Democrats.

This time it's a different story. For one thing, a shutdown over the Christmas holiday would likely last for at least two weeks, owing to the congressional schedule, and would therefore be far more damaging to the economy and to the federal government.

Secondly, when Congress returns in January, Trump will no longer have the majority in both chambers. Democrats will take over the House on Jan. 3, while Republicans will add two seats to their current Senate majority.

If Trump doesn't solve the shutdown impasse before January, then Democrats will come sweeping into power, and take credit for solving a problem the president could not.

Most of all, however, Trump's goal of forcing Democrats to own the shutdown is complicated by the fact that Trump has already taken ownership of it himself. On national television, broadcast from the Oval Office.