Second, the bill delivers the goodies now and kicks costs down the road. Mr. McConnell has engineered a deeply cynical, but not uncommon, legislative move: The bill cuts taxes immediately and retroactively, but it pushes draconian health care cuts for the poor and disabled into the future. It is a classic case of Edward Tufte’s “myopic policy for myopic voters.” Mr. McConnell gambles that by delaying the downside to 2020 and beyond, he can muffle and deflect blame when voters hit the polls in 2018.

Third, he’s clearing the deck for tax reform. Republicans prefer to spend their time on taxes, not health care. Under normal Senate rules, action on both issues requires votes from Democratic senators, a tall order in polarized times. Instead, Republicans have submitted to arcane budget rules that let them pass bills with a simple majority, i.e., without the Democrats. But there’s a catch: There’s only one set of tracks that can carry these sorts of filibuster-proof measures, and the rules allow only one train car on the tracks at a time. Granted, Republican cleavage has thus far precluded any progress on taxes. But until health care is off their plate and budgeteers can prepare the next bill, tax reform is stuck in the rail yard.

That’s the bet. Will it pay off?

Skeptics have pointed out that Mr. McConnell is walking a tightrope between the poles of his Republican conference. He can spare the votes of only two of 52 Republicans, relying on Vice President Mike Pence to break a 50-50 Senate tie. What’s more, the bill must still pass muster with complicated budget rules and secure consent of the House and the president. So this is not yet a done deal, at all.

And lots could go wrong. The bill was initially greeted with silence from the president, who called a related House bill “mean” even after feting its passage in the Rose Garden. And on the Hill, a historically divided Republican conference is not yet on board.

On the left of the Republican conference, blue and purple state Republicans reacted skeptically. That’s not surprising given that the related Republican House plan polls terribly among Democratic and independent voters. Other senators need convincing that the bill will meet the particular health care needs of rural states. And the bill’s ban on funding Planned Parenthood for a year jeopardizes the votes of the Republicans’ two lone pro-choice senators.