Former New York City Mayor Mike Bloomberg on Monday issued some advice for a fellow billionaire contemplating a 2020 presidential campaign: Do not run as an independent.

“Now I have never been a partisan guy—and it’s no secret that I looked at an independent bid in the past,” Bloomberg wrote in a statement that conspicuously avoided mentioning former Starbucks CEO Howard Schultz by name. “In fact I faced exactly the same decision now facing others who are considering it.”

“The data was very clear and very consistent,” Bloomberg continued. “Given the strong pull of partisanship and the realities of the electoral college system, there is no way an independent can win. That is truer today than ever before.”

The advice came one day after Schultz confirmed that he is giving serious thought to running in 2020 as a “centrist independent”—an act that Democrats fear would act as a possible spoiler in their efforts to make President Trump a one-term president.

Bloomberg acknowledged in the statement that he has considered running as an independent in past presidential contests, but ultimately concluded that he would enter the Democratic primary if he chose to run this time.

As Schultz embarks on a book tour and publicly toys with his options, Democrats in Washington state have implored him not to run as an independent.

“Howard Schultz running as an independent isn’t about bringing anyone together,” Washington State Democratic Party Chair Tina Podlodowski said Monday. “It’s about one person: Howard Schultz. An independent bid for president has not worked in the past, and it won’t work this time.”

Instead, Podlodowski pleaded that Schultz run for one of the two major party nominations.

“Howard, if you want to run for President, run as a Democrat. If you want to rely on your money to get elected instead of talking with voters, run as a Republican,” she wrote. “But a billionaire buying his way out of the entire primary process does not strengthen democracy; it only makes it more likely that our democracy will be further strained under another four years of President Donald Trump.”