A top Republican with close ties to the White House tells me that after the GOP failure on healthcare, a government shutdown — looming when a continuing resolution runs out April 28 — is "more likely than not... Wall Street is not expecting a shutdown and the markets are unprepared."

And Chris Krueger of Cowen Washington Research Group today will warn financial clients: "Hello April 29 government shutdown."

That's Day 100 of the Trump presidency, by the way.

A senior GOP aide disputed the bearish forecasts: "The White House and Republicans on the Hill cannot/won't risk a shutdown. Given the last week — it's out of the question."