That the sitting President has so much experience with political violence is just one manifestation of how common it has become in the U.S.

Minnesota Democratic Senator Tina Smith joins NBC News' Tom Llamas to discuss the politically-motivated murders in Minnesota. Smith shared that she had seen Rep. Melissa Hortman and her husband Mark the night before their deaths.

The shootings of two Democratic lawmakers in Minnesota are the latest incidents to raise worries about the threat of political violence in the U.S. Experts warn that the attacks, which follow an assassination attempt against President Trump and an arson at the home of Pennsylvania Gov.