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Iowa's longest-serving GOP lawmaker joins the Democrats because of Trump

Washington(CNN) Iowa's longest-serving Republican state lawmaker is ditching the party in a protest of what he called President Donald Trump's "unacceptable behavior" and is joining the Democrats.

State Rep. Andy McKean, a moderate from eastern Iowa whose 29 years in the legislature include stints in the House and Senate, announced his party switch at a news conference Tuesday. He called Trump "a poor example for the nation and particularly for our children" and said he'll seek re-election in 2020 as a Democrat.

"With the 2020 president election looming on the horizon, I feel as a Republican that I need to be able to support the standard bearer of our party. Unfortunately, that is not something I am able to do," McKean said Tuesday of Trump.

"He sets, in my opinion, a poor example for the nation and particularly for our children by personally insulting -- often in a crude and juvenile fashion -- those who disagree with him, being a bully at a time when we are attempting to discourage bullying, his frequent disregard for the truth and his willingness to ridicule or marginalize people for their appearance, ethnicity or disability," he said.

The move -- which narrows the GOP's hold on the state House to 53 seats to Democrats' 47 -- is an embarrassment for Trump in a state that's under a constant political microscope due to its role as the first to cast votes in presidential nominating contests. Democratic presidential contenders will battle for the next nine months ahead of the state's caucuses next year.

Iowa is also a swing state -- former President Barack Obama won it twice -- that had shifted rapidly in Republicans' favor in recent years. Trump won there in 2016 by nearly 10 percentage points. If Iowa is in play in 2020, it would be a sign that the Midwest had slipped away from the President.

McKean's explanation also speaks to the political challenges facing some Republicans across the nation about whether to stand with a President who has brazenly disregarded the traditional norms of decorum that for centuries have defined the office. His defection also comes soon after the release of a redacted version of special counsel Robert Mueller's investigation into Russian meddling in the 2016 election revealed a President and administration that frequently lie on an array of matters.

"I believe that it is just a matter of time before our party pays a heavy price for President Trump's reckless spending and shortsighted financial policies, his erratic, destabilizing foreign policy and his disregard for environmental concerns," added McKean, whose district sits in two rural, blue-collar counties in Iowa, Jones and Jackson.

"If this is the new normal, I want no part of it."

Republicans in Iowa vowed retribution against McKean.

"When Rep. McKean ran in 2016, he had no problem riding to victory on Pres. Trump's coattails. He's about to feel the headwind of Pres. Trump's support in District 58," Iowa Republican Party chairman Jeff Kaufmann tweeted.