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Julián Castro, a former Housing and Urban Development secretary under President Barack Obama and an announced contender for the 2020 Democratic presidential nomination, urged Sunday that former Starbucks CEO Howard Schultz not pursue an independent bid for the presidency.

Speaking on CNN's "State of the Union," Castro said Schultz, a Democrat for whom he said he has "tremendous respect," should "think about the negative impact" of any potential independent presidential run.

"I have a concern that if he did run, that, essentially, it would provide Donald Trump with his best hope of getting re-elected,” Castro said. “Just the other day, there was a fairly comprehensive poll taken that showed, essentially, right now, that the President has a ceiling of about 41 or 42 percent, in terms of support for him, no matter which Democratic candidate they polled against him."

"So his only hope, if things stayed the same — and that’s a big if — is essentially to get somebody else, a third party, to siphon off those votes," he continued.

In a "60 Minutes" interview airing Sunday, Schultz said he is very seriously considering an independent presidential bid.

Schultz told CBS News' Scott Pelley in the interview that Trump is "not qualified to be the president," adding that "both parties are consistently not doing what’s necessary on behalf of the American people and are engaged, every single day, in revenge politics."

Schultz is worth $3.3 billion, according to Forbes.