Republican presidential challenger and former South Carolina Rep. Mark Sanford cautioned that while an impeachment inquiry into President Donald Trump is justified, it could significantly quash discourse in both parties leading up to the 2020 presidential election.

"It becomes the giant elephant in the room and all political discussion, if you will, stops," Sanford told CNN's Jim Sciutto Monday on "New Day."

Sanford's comments come in the aftermath of House Speaker Nancy Pelosi announcing an impeachment inquiry last week that is slated to focus on the President's dealings with Ukraine -- a move that some critics fear could serve to rally the Republican base around the President.

While he thinks an inquiry is "substantively" justified, Sanford said that "it will bring tremendous discord within the political system that will then usurp the electoral process that's now taking place on the Democratic side, and on the Republican side what happens is that people circle the wagons."

The South Carolina Republican said that the "fairly robust" Democratic debate process currently "is usurped by the larger debate on impeachment and what comes next."

On the Republican side, "they feel as if their President is under threat," he added. "They circle the wagons that much harder and makes it that much more difficult to get your word out if you're a challenger."

Sanford pointed to impeachment not having an overwhelming majority as a reason to consider its future implications given the possible outcomes of the 2020 election.

"If the waters simply stay quiet, there are great probabilities in terms of outcome next November," he said. "Why do you want to throw this into the mix, given the way that that could throw that all off to the side, and who knows what comes next?"

Sanford said that he expected support among staunch Trump supporters to intensify, but for undecided voters at large to remain "open to this, based on the fact that it's a very very serious allegation and what we don't want is our foreign policy conducted based on domestic political considerations."