Amna Nawaz

With a stroke of the pen, President Trump issued an ultimatum to U.S. colleges.

AMNA NAWAZ, The executive order signed today requires colleges to certify that their policies support free speech as a condition to receiving federal research grants. It doesn't affect schools' access to federal financial aid for student tuition. President Trump first proposed the idea to a gathering of conservatives in Washington earlier this month.

He brought on stage conservative activist Hayden Williams.

In February, Williams was recruiting on UC Berkeley's campus when he got into an altercation with this man, who then punched Williams in the face. That man was arrested and charged with assault, and the university condemned the attack. Williams spoke to the NewsHour while in Washington earlier this month.