Pro-Impeachment Amash leaves the GOP — and issues scathing rebuke of Mitch McConnell’s leadership

Rep. Justin Amash (R-MI), the only Republican lawmaker who backs an impeachment inquiry for President Donald Trump, announced that he's leaving the GOP.

The Michigan Republican faces a tough primary challenge from the Trump-supporting state Rep. Jim Lower, denounced the two-party system as "an existential threat to American principles and institutions" in a scathing op-ed published on the Fourth of July in the Washington Post.

"Today, I am declaring my independence and leaving the Republican Party," Amash wrote. "No matter your circumstance, I’m asking you to join me in rejecting the partisan loyalties and rhetoric that divide and dehumanize us. I’m asking you to believe that we can do better than this two-party system — and to work toward it. If we continue to take America for granted, we will lose it."

Amash pointed to George Washington's warnings about partisanship in his farewell address.

"True to Washington’s fears, Americans have allowed government officials, under assertions of expediency and party unity, to ignore the most basic tenets of our constitutional order: separation of powers, federalism and the rule of law," Amash wrote. "The result has been the consolidation of political power and the near disintegration of representative democracy."

Amash's own farewell to the Republican Party included a scathing rebuke of Senate Majority Leader Mitch McConnell's tenure.

"These are consequences of a mind-set among the political class that loyalty to party is more important than serving the American people or protecting our governing institutions," he wrote. "The parties value winning for its own sake, and at whatever cost. Instead of acting as an independent branch of government and serving as a check on the executive branch, congressional leaders of both parties expect the House and Senate to act in obedience or opposition to the president and their colleagues on a partisan basis."