Story highlights "Well, I think all of us realize that if we fail on taxes, that's the end of the Republican Party's governing majority in 2018," Graham said.

"They'd try to impeach him pretty quick and it would be just one constant investigation after another," Graham added.

(CNN) South Carolina Republican Sen. Lindsey Graham said Friday that if Republicans don't pass tax reform, then Democrats will take back the House of Representatives and attempt to impeach President Donald Trump.

"Well, I think all of us realize that if we fail on taxes, that's the end of the Republican Party's governing majority in 2018," Graham said on Fox News Radio's "The Brian Kilmeade Show." "We'll lose the House, probably lose ground in the Senate and President Trump has got a profile different from the party -- there's kinda two or three different Republican Parties now, I guess. But we're all in it together."

"I can't imagine how he could be successful with Nancy Pelosi running the House," Graham continued. "They'd try to impeach him pretty quick and it would be just one constant investigation after another. So it's important that we pass tax reform in a meaningful way. If we don't, that's probably the end of the Republican Party as we know it."

On Thursday, the House passed a budget resolution that clears the path for Congress to tackle tax reform legislation. House Republicans are expected to unveil their tax reform legislation on November 1, with plans for the bill to move rapidly through both chambers in the following weeks.