The reversal halts a push began just last week to find an alternative and guarantees that the issue will take center stage in the 2020 campaign.

The position is a change for the DOJ after it argued last year that large parts of the 2010 law -- but not all of it -- should be struck down.

Legislation proposed by Congressional Progressive Caucus co-chair Pramila Jayapal would steer all Americans into the Medicare program in two years.

A majority of Americans support a national “Medicare for All” system, according to a new survey from KFF.

Making single-payer health care the progressive position opens a door for more modest proposals to expand the government's role in health insurance.

More than 400 companies have also signed on to efforts with ElectionDay.org and Time to Vote to boost voter turnout in a variety of ways.

"It's no secret that we preferred to start over," McConnell said of Republican efforts repeal and replace Obamacare.

The issue of pre-existing conditions has put Republican candidates from conservative states and swing House districts on the defensive.