As if cutting $1 billion for cancer research wasn't bad enough, President Trump's 2018 budget proposal, unveiled Tuesday, is based on a massive error—of approximately $2 trillion. Meanwhile, Trump is out of the country on his first foreign trip, which continues Thursday in Brussels. 

"He might want to stay," "Late Show" host Stephen Colbert opened Wednesday. "Till the firemen can put out his budget proposal."

"Not only does nobody like it," he added, "but it turns out it has a huge mistake in it... it turns out that the entire budget is based on a $2 trillion math error."

The giant blunder is likely due to one of two issues.

Either "Donald Trump is an idiot... or he's lying," explained Colbert. "Because the budget claims there will be magically $2 trillion of new tax revenue from economic growth when we cut rich people's taxes... and then... it factors in the same made-up $2 trillion again as a way to offset that tax cut for the wealthy." 

"That's like robbing Peter to pay Paul, but you're paying Paul with a Blockbuster gift certificate," he concluded. 

Of course, this isn't all Trump's fault; Budget Director Mick Mulvaney, who was shunned by the House budget committee while presenting the plan Wednesday, later received ample shade from Colbert.

To close, the host rebuked Trump's fuzzy math with a simple suggestion.

"If a train leaves Washington, D.C., traveling at 40 miles an hour, please get on it... just go east, actually." 

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