Appearing on "America's Newsroom" with host Sandra Smith, Gingrich said that looking at the timeline is "astonishing."
"He's declared the winner about 2:30 AM and the next day you already have eight or nine cities where left-wingers have organized anti-Trump rallies," he told Smith.
"By December 15th, you have a Vanify Fair article about how the impeachment process is underway. And, on the very day that the president is sworn in, January 20, 2017, The Washington Post has a story about the Democrats planning for impeachment," said Gingrich.
"So, Nancy Pelosi is simply carrying out what is an unconstitutional coup d'etat -- an effort to use the power of the Congress to change the outcome for the American people," Gingrich explained.
"And, it's a direct assault on the whole idea of representing the American people. And, instead, imposing Democratic members of Congress as the ultimate electoral college. And, I think it will backfire very badly," he said.
Gingrich added that there are serious questions about corruption in Ukraine.
"It's legitimate to ask questions about that corruption. ... I think the Democrats are terrified that if the president is actually able to pursue this, that in fact it will change the whole nature of our understanding of what happened over the last few years," Gingrich concluded.