Iowa’s longest-serving Republican legislator, Andy McKean, ditched the GOP on Tuesday as he offered a searing renunciation of Trump, saying he could no longer support POTUS because of his “unacceptable behavior”.

At a press conference on Wednesday McKean revealed he would join the Democratic Party, a decision he described as “very difficult” after spending 50 years as a registered Republican and serving 26 years in the state legislature as a member of the GOP. McKeen:

I feel as a Republican that I need to be able to support the standard-bearer of our party. Unacceptable behavior should be called out for what it is, and Americans of all parties should insist on something far better in the leader of their country and the free world.

McKean joins other state Republican officials around this once great nation who have fled their party amid a divisive presidency and shifting political landscape. From Kansas to New Jersey, a slow succession of state lawmakers and officials, largely in suburban districts that have become less red, has both startled constituents by leaving the GOP, oftentimes citing Trump’s hateful rhetoric and policies and a disagreement with the party’s responses to his behavior.

As the 2020 election approaches, McKean says:

I feel as a Republican that I need to be able to support the standard-bearer of our party. Unacceptable behavior should be called out for what it is, and Americans of all parties should insist on something far better in the leader of their country and the free world.

I believe his actions have coarsened political discourse, have resulted in unprecedented divisiveness and have created an atmosphere that is a breeding ground for hateful rhetoric and actions. Some would excuse this behavior as ‘telling it like it is’ and the new normal. If this is the new normal, I want no part of it.

McKean’s surprise announcement comes as Republicans are grappling with how to respond to the damning look at the current presidency presented in the Mueller Report. On Tuesday, J.W. Verret, a law professor at George Mason University and a member of Trump’s 2016 transition team, published an essay in Atlantic magazine detailing why the report has led him to feel comfortable calling for impeachment, even though he is a longtime Republican. Verret:

I wanted to share my experience transitioning from Trump team member to pragmatist about Trump to advocate for his impeachment, because I think many other Republicans are starting a similar transition.

McKean intends to run for reelection as a Democrat in 2020.