The list of Senators supporting Bernie's Medicare-for-all bill is growing by the day.

Is single-payer healthcare on the verge of becoming the default position of the Democratic Party?

Oregon's Jeff Merkeley, New Jersey's Cory Booker, New York's Kirsten Gillibrand and Rhode Island's Sheldon Whitehouse are officially on board the single-payer train.

All four senators revealed yesterday they are co-sponsoring Bernie Sanders' Medicare for all bill, which is set to be introduced later this week.

Booker revealed his decision during an interview with New Jersey public television:

"I'm signing onto Medicare-for-all, which I'm excited to do this week. Senator Sanders and myself and others are going to be announcing some legislation. I'm signing on to some other with my colleagues, all of us working towards this understanding that if you look at American history, it's always been advancements towards greater equality, greater access, greater opportunity."

Now, in my opinion Bernie could have won the presidential election, and now it appears as though his policies are winning over the Democratic Party.

Is single-payer now all-but inevitable, at least as the mainstream Democratic position?