Many have said the person being hurt the most by Trump’s impeachment probe, is not the president, but his Democratic rival, former VP, Joe Biden. This seems to be the case as Biden has dropped in the polls since the impeachment inquiry began and now finds himself in a statistical dead heat with Senator Bernie Sanders.

With only three days until the next scheduled Democratic presidential debate – which will be held on Thursday Dec.19 in California — a new national poll indicates that Biden and Sanders are in a virtual tie at the top of the still large field of White House hopefuls.

Biden – who has remained at the top of nearly every national poll since even before he declared his candidacy in late April — stands at 24 percent among Democrats and Democratic-leaning independents voters in an NPR/PBSNewsHour/Marist poll released Monday.

Sanders, the populist senator from Vermont who is making his second straight run for the Democratic nomination, is at 22 percent. Biden’s slight 2-point edge is within the survey’s sampling error, which means the two are in a statistical dead heat.

Massachusetts Sen. Elizabeth Warren – who has also consistently been a “top-tier” contender, but whose numbers have been slipping of late, stands at 17 percent in the poll. South Bend, Indiana Mayor Pete Buttigieg – a onetime long-shot who’s soared in recent months in surveys in the early voting states of Iowa and New Hampshire – came in at a respectable 13 percent.

According to the poll, tech entrepreneur Andrew Yang is at 5 percent, with Sens. Cory Booker of New Jersey, Amy Klobuchar of Minnesota and former New York City Mayor Mike Bloomberg each at 4 percent. Sen. Michael Bennet of Colorado, Rep. Tulsi Gabbard of Hawaii, and former Obama housing secretary and former San Antonio, Texas Mayor Julian Castro stand at 1 percent. Every other candidate registered at less than 1 percent.

However, the poll indicated that with a month and a half to go until the Iowa caucuses kick off the presidential nominating calendar, just over three-quarters of those questioned said they could “change their minds” on who they are currently supporting.

Meanwhile, ongoing labor disputes in California between union workers and the venues for the debate, threaten to sideline the event. A labor union called UNITE HERE Local 11, says it will picket outside the event, which is now scheduled at  Loyola Marymount University after a similar dispute forced it to move from UCLA, where it was originally scheduled. Massachusetts Sen. Elizabeth Warren and Vermont Sen. Bernie Sanders responded by tweeting they wouldn’t participate if that meant crossing the unions picket line. Former Vice President Joe Biden, Mayor Pete Buttigieg of South Bend, Ind.; Minnesota Sen. Amy Klobuchar, environmental activist Tom Steyer, and businessman Andrew Yang all said the same.

UNITE HERE Local 11 says it represents 150 cooks, dishwashers, cashiers and servers working on the Loyola Marymount campus. It says it has been in negotiations with a food service company since March for a collective bargaining agreement without reaching a resolution, and “workers and students began picketing on campus in November to voice their concern for a fair agreement. The company abruptly canceled scheduled contract negotiations last week.”