Is socialized healthcare a litmus test for Democrats in 2018?

A surge of Democratic support for socialized healthcare is sparking new questions over whether the issue is becoming a litmus test for Democrats ahead of the 2018 midterm elections.

Single-payer healthcare, or a healthcare system run by the federal government, has largely been on the sidelines of the Democratic Party's policy platform, but that is quickly changing as Sen. Bernie Sanders, I-Vt., gains clout in the party and Republicans struggle to repeal Obamacare.

Sanders is expected to release a new version of his Medicare-for-all single-payer healthcare plan soon. He has pushed for the system for years while in both the House and Senate and touted a similar plan when he challenged Hillary Clinton last year for the Democratic presidential nomination.

While universal healthcare has been a plank in the Democratic Party's platform, party leadership has long shied away from embracing the idea for fear it could cost them support from centrist or independent voters.

But support is growing among the public for the idea. A June poll from Pew Charitable Trusts found that 60 percent of those surveyed believe the federal government is responsible for ensuring healthcare coverage for all Americans, compared with 39 percent who do not.