The University of Minnesota canceled one of its biggest annual lectures, a December speech set to be delivered by Michael Bloomberg, citing the former New York City mayor's likely entrance into the presidential race.

The Humphrey School of Public Affairs said Friday that it had to "reassess the possibility of hosting" its Distinguished Carlson Lecture given recent reports that Bloomberg would soon declare a run for president. His speech was announced in October. But according to the U, university policy and federal laws bar the public entity from activities that may support current presidential candidates, regardless of when they were originally scheduled.

"For this reason, the Humphrey School has decided not to move forward with this event," the school said in an e-mail.

A high-profile Bloomberg address on the Minnesota campus could have been a sore spot for Minnesota U.S. Sen. Amy Klobuchar, who has been trying to court moderate-leaning voters since launching her campaign a few miles upriver in February.

Despite not yet officially declaring his intentions to run, Bloomberg, a billionaire businessman, launched a $100 million digital ad campaign on Friday attacking President Donald Trump in Arizona, Michigan, Pennsylvania and Wisconsin.