A Roy Moore victory on Dec. 12 could speed up efforts to impeach President Donald Trump, a Republican strategist said.

Alex Castellanos, former media advisor to President George W. Bush, told ABC's George Stephanopoulos a combination of events - including Moore's controversial Alabama Senate campaign - could signal trouble for the White House.

"Two converging currents, the (Robert) Mueller investigation, looking for that obstruction of justice charge, and then Alabama. Roy Moore coming to the Senate possibly in a week," Castellanos said. "(Moore) becomes the face of the Republican Party for the next year when we're already in danger of losing the House.

"It's likely that we'll do that without (Moore), lose the House," he continued. If so then "Trump gets impeached. We're closer to impeachment now I think than we think."

Controversy has been swirling around Trump since he fired FBI Director James Comey and a subsequent investigation by Special Counsel Mueller into Russian interference in the 2016 presidential election. Trump's former National Security Adviser Michael Flynn pleaded guilty last week to charges he lied to the FBI and is cooperating with the investigation.

The president has denied any wrongdoing.

Trump has also been under fire for his support of Moore, who has been accused of having sexual contact with teenage girls in the 1970s. Moore denies the charges.

The combination of the two events could derail Republican efforts to keep control of Congress in the mid-term elections, raising the specter Democrats could step up impeachment efforts. Democrats need 24 seats to win back the House. A majority in the House would have to vote for impeachment; a two-thirds vote is required in the Senate.

The Alabama Senate election is Dec. 12.