If you’re looking for more evidence that the Elizabeth Warren boom might be coming to an end, look no further than the latest Emerson College poll of Democratic Iowa caucus voters. Only Mayor Pete Buttigieg has remained steady, holding at 18% this month compared to 16% in October. Outside of that, Elizabeth Warren took a beating while Bernie Sanders has jumped back into a statistical tie with former vice president Joe Biden.

While Warren’s drop is significant, it’s also noteworthy that Bernie has experienced a bit of resurgence compared to the previous numbers jumping 9 points since October:

The most movement in this poll, as compared to the last Emerson Poll in October, is Warren’s downward slide from frontrunner status, and Sanders’ subsequent gain. Warren and Biden had 23% each in October. While Biden held his numbers in this poll, Warren fell 11 points. Sanders may have benefited from Warren’s loss of support, surging to 22% from 13% of the vote in October. Buttigieg maintained steady support over the last two months, gaining slightly from 16% in October to his current 18% of the vote. Amy Klobuchar experienced a huge leap from noncompetitive numbers – just 1% in October – to 10%.

Continuing the trend evident in previous Emerson polls, Sanders leads among those under 50 with 32% support. Following him in that group, is Warren with 16%, Buttigieg with 13%, Biden with 11% and Klobuchar with 8%. Among those 50 and over, Biden leads with 36% support, followed by Buttigieg with 23%, Klobuchar with 13%, Sanders with 11% and Warren with 8%.

Here’s the complete chart courtesy of Emerson:

For a variety of reasons, Warren started tumbling in October and November and has been on a downward trajectory ever since. Pete Buttigieg’s numbers have been steady according to this poll, but others show his momentum slowing. It’s also noteworthy that Joe Biden fell five points since the October Emerson numbers to his current 23%.

That leaves Bernie Sanders as the biggest winner in December jumping nine points since October. The Sanders campaign has been complaining of media bias, specifically bias of ignoring the Vermont Senator’s resurgence as of late in a variety of polls.

Maybe the question isn’t about Buttigieg and Biden, but rather it should be about Biden and Sanders. If there’s one candidate who has been consistent in his views and his forceful political stances it’s Bernie Sanders. The certainty of his views sometimes gets him in trouble, but it can also be endearing to voters looking for clear contrasts.

Don’t look now, but Bernie is back on top in New Hampshire as well after ceding the top spot to Pete Buttigieg for a couple of weeks. Take that data point with this new Iowa poll, and the California poll from days ago and it’s arguable that Bernie’s back in the driver’s seat, at least in some states.