(CNN) Former Speaker of the House and Trump ally Newt Gingrich said Thursday that if Democrats subpoena President Donald Trump, Republicans will see whether Supreme Court Justice Brett Kavanaugh's tumultuous confirmation process "was worth it."

During a live interview hosted by The Washington Post on Thursday evening, political columnist Karen Tumulty asked Gingrich what he expected should Democrats, who could win a majority in the House of Representatives in the coming midterm elections, subpoena Trump's tax returns.

"Then they'll be trapped into appealing to the Supreme Court, and we'll see whether or not the Kavanaugh fight was worth it," Gingrich replied.

When Tumulty asked why Trump seemed to be "raising that fear" of being investigated by Democrats, Gingrich said, "That's because he wants everyone to go vote."

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