Mark Shields said on PBS "NewsHour" last night what a lot of Republicans privately tell us they fear about health reform: "We've just seen the high water mark for this legislation."

A top Republican emails me: "I think the reality of the Senate process is setting in."

The legislation is likely to take a month or two to wend through the Senate. And Republicans are queasy about getting the likely result back through the House, then to President Trump's desk.

As Peter Baker told Bob Costa on "Washington Week" about the Rose Garden celebration:

"You had the president of the United States and dozens of members of his party there on the lawn, very boisterous, very happy, very jubilant about something that hasn't happened yet. It's one thing for the House to pass; that doesn't make it a law. ... So when he says that Obamacare is dead, Mark Twain would have something to say about that."

The vote's political fallout has been instant, emboldening Ds and chastening Rs:

Atop the N.Y. Times' column 1, "DEMOCRATS FOCUS ON BILL'S STANCE ON PRIOR ILLNESS: HEALTH CARE THIRD RAIL — Looking to 2018, With Stress on Pre-existing Conditions," by Alex Burns and Abby Goodnough: "Groups on the left posted graphics online listing pre-existing conditions that could, in theory, threaten health care coverage, with some shared hundreds of thousands or millions of times."

And Republicans have a self-inflicted reason to be defensive. After the white-guy photo from the House ceremony in the Rose Garden, CNN's Erin Burnett pointed out that 13 white men are tackling health care in the Senate: "There are big medical differences between men and women." Drops mic.

Axios AM prediction: Susan Collins will be added to the table.