No. Matter. Who.

First things first: If you are a Democrat, the only valid answer to the question "will you support the Democratic nominee regardless of who it is?" is "yes." No hemming. No hawing. No "it depends." Yes.

I don't care whether the nominee is Biden or Warren or Sanders or Klobuchar or Bloomberg or Tulsi frickin' Gabbard. The answer is yes.

So: Joe Biden gets today's tsk of shame for not answering this question correctly:

Former Vice President Joe Biden stopped short Tuesday of saying he’d support Bernie Sanders if the progressive Vermont senator wins the Democratic presidential nomination.

“I’m not going to make judgments now,” Biden told reporters in Muscatine, six days before the Iowa caucuses. “I just think that it depends upon how we treat one another between now and the time we have a nominee.”

Bzzzt. Wrong answer. The correct answer is "yes", without further adornment. See above.

But a new poll suggests that while Biden-the-candidate may be getting it wrong; at least his supporters are getting it right. And as for Bernie Sanders -- well, vice versa. He's taken the right line on the issue, but his supporters....

Only a small majority of Bernie Sanders voters say they will definitely support the eventual Democratic nominee at the 2020 election if the independent Vermont senator does not win the race, according to a poll.

The National Emerson College Poll of 1,128 registered voters between January 21 and January 23 found that 53 percent of Sanders supporters said "yes" when asked if they would support the Democratic nominee even if it is not their candidate.

Another 31 percent of Sanders supporters said it depends on who the nominee is and 16 percent flat-out said no. The poll, conducted via landline calls and an online panel, has a 2.8 percentage point margin of error.

The poll suggests some Sanders supporters are out of step with their own chosen candidate on the question of supporting the Democratic nominee regardless of who it is.

"Let me be clear: If any of the women on this stage or any of the men on this stage win the nomination—I hope that's not the case, I hope it's me—but if they do I will do everything in my power to make sure that they are elected in order to defeat the most dangerous president in the history of our country," Sanders said at the recent Iowa debate.

By comparison to Sanders, 87 percent of former vice president Joe Biden's supporters said yes to voting for whoever wins the nomination, 9 percent it depends on the winning candidate, and 5 percent said no to anyone that is not Biden.

And 90 percent of Massachusetts Senator Elizabeth Warren's supporters said they would vote for whoever is the nominee, while the remaining 10 percent said it depended on who won the nomination.

None of Warren's supporters said they would not vote for the eventual nominee if she loses the Democratic race.

Chalk this up as another data point in favor of "Bernie Sanders" being far, far superior to "Bernie Sanders supporters."