The business mogul wrote in an article for Bloomberg View that he is concerned his theoretical third-party run could have split votes and led to what he sees as an unfortunate outcome, pointing out that after looking at the data, “it’s clear to me that if I entered the race, I could not win.”

After speculation that he might enter the race, Bloomberg confirmed in February that he was indeed exploring the possibility. But he said it was now time to end that exploration, “because of ballot access requirements.”

In the piece, titled “The Risk I Will Not Take,” he wrote that a three-way race likely would not result in one candidate winning a majority in the electoral college, which would send the decision to Congress. “As the race stands now, with Republicans in charge of both Houses, there is a good chance that my candidacy could lead to the election of Donald Trump or Senator Ted Cruz,” he wrote. “That is not a risk I can take in good conscience.”

Acknowledging that he has long known Trump “on friendly terms,” he said the Republican frontrunner “has run the most divisive and demagogic presidential campaign I can remember, preying on people’s prejudices and fears.” He said Cruz’s position on immigration “may lack Trump’s rhetorical excess, but it is no less extreme.”

Bloomberg wrote that he was not yet ready to endorse a candidate, but invoked Abraham Lincoln in urging voters to stand up for “the last best hope of Earth.”

Hillary Clinton said during a Fox News town hall that she had the “greatest respect” for Bloomberg and hopes to work with him in the future. Her Democratic rival, Bernie Sanders, said at the same event that he was concerned that Bloomberg is a billionaire and that the idea that only the rich could run for president is dangerous.

This article was originally published on Time.com.