Threats and violent acts have become part of the political landscape, still shocking but somehow not so surprising.

The killing of a Minnesota lawmaker and her husband sent shockwaves through the political world and appeals from elected officials to turn down heated rhetoric.

The assassination of a Democratic Minnesota state lawmaker and her husband and the shooting of another lawmaker and his wife at their homes are just the latest addition to a long and unsettling roll call of political violence in the United States.

One of the debilitating aspects of any violence is how final and definitive it is and how anemic any response to it feels. Capturing and trying the alleged culprit are necessary next steps but nothing unwinds what was done.

U.S. Capitol Police increased security for Klobuchar and Smith following the attacks, which occurred early Saturday morning. Minnesota's entire congressional delegation, both Republicans and Democrats, released a joint statement condemning the killings.

While Washington hosted a military parade, large crowds gathered across the country Saturday to peacefully protest President Donald Trump’s policies. The threat of violence – and news of a political assassination in Minnesota – added to tensions.

The attacks on two Democratic Minnesota state lawmakers at their homes are the latest in a grim and alarming surge of U.S. political violence.

Authorities are on the second day of the hunt for a man suspected of killing Minnesota State Rep. Melissa Hortman and her husband at their house. The suspect also is believed to have shot State Sen. John Hoffman and his wife in their home.