Updated

Former UBS America Chairman and CEO Robert Wolf told “America’s Newsroom” Tuesday that the race for the Democratic nomination has been “incredibly disappointing” because “the field hasn’t winnowed.”

“Now Bernie [Sanders] is the frontrunner, but he’s a frontrunner [with] 25, 30 percent [of the vote], Nevada aside, and I think it feels like it is either plurality for him or we’re going to some sort of tough contested convention,” said Wolf, a former economic adviser to President Barack Obama.

Wolf spoke hours ahead of the South Carolina Democratic presidential debate and Saturday’s primary after Sanders strengthened his status as the clear front-runner with a decisive win in the Nevada caucuses, worrying many members of the Democratic establishment that there may be no path to stop him before the party's convention in July.

With all of the Nevada returns in, Sanders had 46 percent of the vote, followed by former Vice President Joe Biden at 20 percent  -- his best finish in any of the first three contests -- and former South Bend, Ind. Mayor Pete Buttigieg at 14 percent.

SANDERS' WIN IN NEVADA REINFORCES HIS FRONT-RUNNER STATUS, DRAWS MORE ATTACKS FROM RIVALS

“I think Joe Biden had a good week and I don’t think he’s getting much play for it, but he had north of 20 percent [in] Nevada and Mayor Pete not getting 15 percent helps him [Biden] with delegates,” Wolf said before predicting that Biden would win South Carolina.

Wolf then noted that the Democratic Party likes “hope and change” as well as “young” and “aspirational.”

“We haven’t had a Democratic president since before JFK over the age of 53," he pointed out, adding that this election season "is incredibly unique" given most of the top candidates are much older than that.

“So it was all about electability, now it’s actually about who can get out the vote and Bernie’s showing that his message is working.”

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“That being said, I think the moderates are the silent majority and because we haven’t coalesced around any one candidate, that’s been what I think is the disappointment of the primary season,” he continued.

Fox News’ Tyler Olson contributed to this report.