Vermont Sen. Bernie SandersBernard (Bernie) SandersClinton backs Georgia governor hopeful on eve of primary The Hill's 12:30 Report — Sponsored by Delta Air Lines — Frenzy over Kennedy retirement rumors | Trump challenges DOJ Bernie Sanders announces Senate reelection bid MORE (I), who recently entered his name into the mix of possible presidential contenders for 2016, questioned potential opponent Hillary ClintonHillary Diane Rodham ClintonClinton backs Georgia governor hopeful on eve of primary Pressure rising on GOP after Trump–DOJ fight’s latest turn Press: Why Trump should thank FBI MORE's commitment to "working families" in an interview.

Speaking to Salon, Sanders prefaced his critique with a compliment, saying he likes Clinton and believes she is "extremely smart."

"But it’s — we will have to see what she has to say, so — but based on the kind of centrist positions that we have seen her take in the past, it remains to be seen — although I may be wrong — it remains to be seen whether she will be a forceful advocate for working families," he added.

Sanders told the Burlington Free Press that he'd run for president in 2016, likely as an independent, if none of the Democratic candidates end up espousing sufficiently progressive views.

He said in the Salon interview that he's largely running to keep many of those issues in the national spotlight.

"The nature of media is that presidential campaigns and candidates are a means, to some degree at least, of getting these issues out there. And I think that you can give all the speeches you want on the floor of the Senate, that’s great, but I think being involved in debates and being out there around the country allows — gives you the opportunity to talk about these issues in a way that you otherwise could not," Sanders said.

The self-described socialist would have a difficult time gaining traction in the race, however. Clinton is expected to run and, if she does run, she's expected to easily lock up the Democratic nomination.

Still, progressive groups in recent weeks have questioned her commitment to progressive ideals. Many have suggested Massachusetts Sen. Elizabeth Warren (D) as a progressive alternative to Clinton.