Turn the bill this way, turn it that way, plead, persuade, threaten, bargain — until 50 out of 52 Republican senators are won over.
If he can pull off that fiendishly difficult task, he wins.
His prize? The federal government will spend hundreds of billions less on health care. Spending on Medicaid, the main program covering low-income Americans, will fall dramatically. Millions of people — tens of millions, by the latest estimates — will lose their health insurance. Years more instability and bitter political conflict over health care will ensue.
And the Senate majority leader would get a historic legislative achievement to his name. "Every Republican senator has been elected or reelected on repealing Obamacare. And he's a guy who wants to win," one McConnell insider told me.
But the cost will be that the legislative body he leads and has long claimed to deeply value will be changed forever.
That's because the tactics McConnell is using to get his win — which have entailed previously unimaginable amounts of secrecy, speed, and utter disregard for public opinion — are a blueprint that future Senate majorities will surely use for their own purposes.
"McConnell has unleashed a whole series of forces that ultimately could really transform the Senate in a bad way," says Norm Ornstein of the American Enterprise Institute. "And if these tactics succeed, they're going to be emulated."
This is ironic because McConnell has long claimed to have deeply held beliefs about the unique role the Senate should play in American politics.
Because a simple majority is not enough to get things done in the Senate, the chamber is a "moderating institution" that should "keep the government from swinging between extremes as one party loses power and another gains it," he wrote in his memoir, The Long Game.
"When the Senate is allowed to work the way it was designed to, it arrives at a result that's acceptable to people all along the political spectrum," McConnell argued in a major 2014 speech. But if it is used as "an assembly line for one party's partisan legislative agenda," then the consequence would be "instability and strife" rather than "good, stable law."
The speech was titled "Restoring the Senate." Instead, McConnell's legacy may be breaking it.