Fact check: Trump vs. Grassley on tax cuts in history

President 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.

A look at the matter:

Trump: "I'm giving the largest tax cuts in the history of this country." — comments Tuesday after meeting Henry Kissinger.

The facts: His tax plan is, at most, fifth largest in its estimated cost, says Marc Goldwein, senior vice president and policy director at the nonpartisan Committee for a Responsible Federal Budget. It could well end up being even lower on the ladder historically.

The estimated cost of the tax plan has dropped by half or more since the spring, when only the contours were known. In an analysis in April, Goldwein's group found that the $5.5 trillion plan that was then expected would have been the third largest since 1940 as a share of GDP, behind President Ronald Reagan's package in 1981 and tax cuts enacted in 1945 to phase out revenue generated for World War II.

But, citing estimated costs of $1.5 trillion to $2.5 trillion for Trump's plan now, Goldwein said several other historically significant tax cuts also would surpass Trump's: from 2013 and 1964.

Trump frequently overstates the size of his tax plan, though on some occasions he's called it one of the largest.

Grassley: "Here are the fact fr my own self Fact Checker. When I chaired Finance 2001 $1.35T adjusted for inflation =2016 $1.865T in tax cuts 2003 350B=2016 $468B 2005 $70B=2016 $88B." — tweet Thursday.

The facts: That statement is in the ballpark, if migraine-inducing. Combining three rounds of tax cuts under Bush yields a package bigger than Trump's would be even if it tops out at $2.5 trillion. It's also conceivable that the first round of Bush tax cuts alone, worth over $1.3 trillion in 2001 dollars, would be bigger than Trump's package. Grassley is "basically in the right," Goldwein said.

Having worked to pass the Bush tax cuts as chairman of the Senate Finance Committee, Grassley wished to set the record straight. But he went on to praise Trump's initiative, in his distinctive Twitter style, saying "regardless ur tax framework sets out badly needed cuts REFORM SIMPLIFICATION TO CREATE JOBS/ move byond ObamaSTAGNATION."