The impeachment inquiry of President Donald Trump is threatening to freeze the Democratic presidential contest in place, at least for the coming weeks, and possibly months.

A year out from the general election, the greatest X-factor for the field of candidates seeking to challenge the president might just be how the impeachment process plays out, and if it makes any new stars in the Democratic field along the way, or takes out any of the front-runners.

House Democrats have been conducting interviews about the administration’s pressure campaign to get Ukrainian President Volodymyr Zelenskiy to investigate former Vice President Joe Biden, and his family, seeking to establish facts for drafting articles of impeachment.

Senate Majority Leader Mitch McConnell, a Kentucky Republican, has been operating on the assumption that the House might send over articles of impeachment against Trump in time for a trial before Christmas, although the House’s timeline may be slipping.

Under the current Senate rules, the chamber would convene daily except for Sundays to hear testimony, with senators sitting as jurors. And there’s been no suggestion that any of the White House contenders who happen to be senators — Bernie Sanders of Vermont, Elizabeth Warren of Massachusetts, Kamala Harris of California, Cory Booker of New Jersey, Amy Klobuchar of Minnesota and Michael Bennet of Colorado — would shirk that responsibility.