(Newser) – The election is about to shift into a higher gear with the start of the new year, and an assessment at Politico asserts that Bernie Sanders is looking stronger than expected as a candidate. The old thinking was that he would have a core of progressive supporters, but not enough widespread support to take the nomination, especially with Elizabeth Warren in the mix. "But in the past few weeks, something has changed," write Holly Otterbein and David Siders. "In private conversations and on social media, Democratic officials, political operatives, and pundits are reconsidering Sanders' chances." More on that and related coverage:

Big momentum: Sanders has shown durability, even bouncing back from a heart attack, while Warren has been generally slipping in the polls of late, per Politico. Don't underestimate him, advises former Obama adviser Dan Pfeiffer. "He has a very good shot of winning Iowa, a very good shot of winning New Hampshire, and other than Joe Biden, the best shot of winning Nevada," says Pfeiffer. "He could build a real head of steam heading into South Carolina and Super Tuesday."

Sanders has shown durability, even bouncing back from a heart attack, while Warren has been generally slipping in the polls of late, per Politico. Don't underestimate him, advises former Obama adviser Dan Pfeiffer. "He has a very good shot of winning Iowa, a very good shot of winning New Hampshire, and other than Joe Biden, the best shot of winning Nevada," says Pfeiffer. "He could build a real head of steam heading into South Carolina and Super Tuesday." Biden's strength? The New York Times has an analysis on Joe Biden suggesting that one of his key strengths is that he might draw the votes of moderate Republicans—or as the story puts it, "the reasonable Republican dad" who won't vote for President Trump. The logic, as laid out by Katie Glueck: Biden "shuns far-reaching proposals like 'Medicare for all'; he has a history of working with Republicans; his warm personal style is disarming; and he represents a return to what some moderates view as a more stable era."