President Trump tweeted Sunday morning that he is "willing to 'shut down'" the government this fall if congressional Democrats don't help to pass his preferred immigration reform.

"I would be willing to 'shut down' government if the Democrats do not give us the votes for Border Security, which includes the Wall! Must get rid of Lottery, Catch & Release etc. and finally go to system of Immigration based on MERIT! We need great people coming into our Country!"

The big picture: I must confess to being surprised by Trump’s tweet — even if he’s made and bailed on such threats in the past. As recently as a month ago, senior White House officials with direct knowledge of the president’s private conversations told me they were convinced he’d been persuaded that it was not in his political interests to shut down the government a month before the midterm elections.

I’ve yet to speak to a Republican member who believes leadership can deliver the wall funding Trump wants by the end of September.

The bottom line: Today’s threat could turn out to be bluster; but if he doesn’t follow through Republican members will fear him less the next time he threatens them.

More from Swan during an appearance on Fox News Sunday: