Former President Barack Obama is becoming more involved in the 2020 presidential election and is ready to speak out against Sen. Bernie Sanders (I-Vermont) if he continued to advance in the polls.

Obama has taken a neutral position in public so far – even withholding from support Former Vice President Joe Biden.

Politico’s Ryan Lizza interviewed a multitude of Obama’s advisers who stated that Obama thinks that his role in the Democratic primary process is to “provide guardrails” to ensure that the election does not become “too ugly.” He is there to “unite the party when the nominee is clear.” There is one exception to this rule, however – Bernie Sanders.

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Obama stated privately that if Sanders became the leading Democratic front-runner, he would speak out and prevent Sanders from becoming the party’s nominee.

When asked whether Obama would actually speak out against Sanders, one of his advisers stated to Lizza that he “can’t really confirm that,” because Obama never directly said so. “The only reason I’m hesitating at all is because, yeah, if Bernie were running away with it, I think maybe we would all have to say something. But I don’t think that’s likely. It’s not happening.”

Sanders identifies as an Independent in the Senate, but he caucuses with Democrats.

Obama has publicly said that he will support whomever becomes the Democratic nominee.

“Look, we have a field of very accomplished, very serious and passionate and smart people who have a history of public service, and whoever emerges from the primary process I will work my tail off to make sure that they are the next president,” Obama told his spokesperson earlier this month.