Vermont Sen. Bernie Sanders has already walked back his accusation that Hillary Clinton is "not qualified" to be president, but he still questioned her "judgment" Sunday morning.

"Well, we were attacked pretty harshly by the Clinton campaign who suggested that I was not qualified," he said on CBS' "Face the Nation," in response to a question about Clinton's qualifications. "We responded by saying you know what, a candidate who receives an enormous amount of money from special interests, a candidate who voted for the war in Iraq, a candidate who voted for virtually every disastrous trade policy which has cost us millions of jobs, well you know what? Maybe her judgment is not quite as high as it should be."

Sanders sharpened his tone against Clinton last week as the campaign heads toward the April 19 New York primary, culminating in him telling a crowd of supporters of Clinton: "I don't believe that she is qualified." He later backtracked, saying on Friday that "of course" she is qualified to be president.

He said Sunday morning that he wants to move on from the conversation about qualifications, noting that he respects Clinton and that she "has enormous experience--everybody who knows her knows she is very intelligent."

"I want to get away from this stuff," he said. "I respect Hillary Clinton, I've known her for 25 years--what I want is a debate on the real issues."

Coming off a victory in Saturday's Wyoming caucuses, Sanders said his recent string of wins is proof that his campaign has momentum.

"That is the eighth victory that we have won in the last nine contests," he said. "There is no question, I think, that we have the momentum. ... I am feeling really great and I believe that we have a real path to victory and at the end of the day we're going to win this."

Sanders also noted that he's cut into Clinton's pledged delegate lead, from over 300 to 258 by CBS News' latest count.

He named New York, Pennsylvania and California as places where he is "closing the gap" in polls--and blamed his delegate deficit on the presence of several Deep South states early on the calendar.

"Look, when we began this campaign we had to deal with the South, the Deep South," he said. "And that's a pretty conservative part of this country, not a stronghold for me."

As for his ultimate role at the Democratic convention, should he lose the nomination to Clinton, Sanders said he will "play an active role in shaping the platform."

Still, he said: "Our plan is to win this thing ... I think we have a real shot to end up with more delegates."

The Vermont senator also touted polling that shows him beating GOP front-runner Donald Trump by bigger margins than Clinton in a hypothetical general-election matchup, saying electability will be high on delegates' minds when they get to the convention in Philadelphia this summer.

"You're going to see a lot of delegates wanting to beat Trump and saying, 'You know, maybe Bernie is the guy to do that,'" he said.