Sen. Steve Daines is proposing an amendment to the Republican healthcare bill that would implement a government-run, single-payer insurance system in the U.S.

The Montana Republican doesn’t support single-payer healthcare. But in a bit of political gamesmanship often seen in Congress, Daines wants to force vulnerable Democratic senators running for re-election in red states in 2018 to take a position on the liberal healthcare policy, which is gaining currency on the Left.