President Donald Trump is going around mischaracterizing his tax plan as the largest tax cut in U.S. history and a Republican senator is calling him out on it.

Iowa Sen. Chuck Grassley tweeted Thursday, as if speaking to Trump, "Ur tax cut will not be 'largest in history of country,'" and proceeded to offer a fact check "my own self."

Grassley then laid out Bush-era tax cuts that were worth more, using nearly incomprehensible Twitterese.