After sweeping the weekend caucuses in Hawaii, Washington, and Alaska, and winning 5 out of the last 6 Democratic nominating contests, Vermont senator Bernie Sanders feels he has the momentum in the race and believes he can still catch Hillary Clinton.

The Hill:

"I think the momentum is with us," Sanders said on CNN's "State of the Union" with Jake Tapper on Sunday. "A lot of these superdelegates may rethink their positions with Secretary Clinton."

The Vermont senator swept Saturday's Democratic contests in Washington, Alaska and Hawaii, easily winning the majority of the 142 pledged delegates in those states. The biggest prize of the day was in Washington, which offered 101 delegates to be split up on a proportional basis.

The latest delegate counts still put Sanders behind Clinton, however, with 1,004 pledged delegates to her 1,712.

Of those, 469 are superdelegates who have pledged to Clinton and only 29 have pledged to Sanders.

Sanders on Sunday said those superdelegates may begin to see the "reality" that he's the best candidate to beat GOP front runner Donald Trump.

"I think when they begin to look at reality, and that is that we are beating Donald Trump by much larger margins than Secretary Clinton" Sanders said. "And then you've got superdelegates in states where we win by 40 or 50 points. I think their own constituents are going to say to them, 'Hey, why don't you support the people of our state and vote for Sanders?'"

Sanders has a point, but the bulk of superdelegates are not likely to bolt – yet.  The next three Democratic nominating contests in Wisconsin (4/5), Wyoming (4/9), and the crucial New York primary on 4/19 will tell the tale if Democrats are going to ride with Hillary or not.

Sanders will be competitive in Wisconsin and likely run away with the Wyoming caucuses.  But if Clinton can't win New York, no matter what the delegate count might be at that point, a lot of party elders will be seriously weighing an alternative to her.  It might not be Sanders, although the Vermont senator runs better against Trump and Cruz than Hillary.  The least controversial alternative would be Vice President Joe Biden.

But in order to get Biden to the podium to accept the nomination, Democrats – like Republicans thinking of supplanting Donald Trump – would have to throw out the convention rulebook.  It can be done, but not without terrible bloodletting on the convention floor and the risk of alienating Sanders supporters.

It will be ironic after heavily criticizing the superdelegate part of the campaign if Sanders depends on them to overtake Clinton and win the nomination outright.