A new poll showing Sen. Elizabeth Warren significantly trailing in her home state of Massachusetts should be a worrisome sign for her candidacy.

Emerson released a poll finding Warren in third place with just 14 percent support in a Democratic primary, much closer to newcomer South Bend, Ind., Mayor Pete Buttigieg (11%), than Sen. Bernie Sanders (26%) or Joe Biden (23%).

This is a pretty embarrassing showing. Emerson's director of polling, Spencer Kimball said, "this is a concern for Warren who at this time does not have a firewall in her home state, and her rival Sanders has a strong base in the Bay State."

But this has implications beyond whether Massachusetts can serve as any sort of firewall for her in the Democratic primary.

What's troublesome is that in national polls or polls of other primary states, it's easy to dismiss her weak polling to this point as a matter of having lower name recognition than Biden or Sanders. Under this theory, as the race develops and voters get to know her more, she stands to rise in the polls.

However, Warren was elected senator in 2012, and in addition to representing the state, she has run two statewide races. And yet, the electorate that knows her best still overwhelmingly prefers Biden and Sanders, and places her well behind, almost at the level of Buttigieg, somebody who few people in Massachusetts ever heard of before a few weeks ago.

It's, no doubt, a long campaign and the field is crowded. Sanders and Biden are both extremely vulnerable. And as I wrote last week, I thought it was a smart move politically for her to come out in favor of getting rid of of the filibuster. But this lackluster performance in her home state has to be seen as a bad sign.