Establishment-minded Democrats are warning primary voters that Bernie Sanders would struggle to defeat President Donald Trump and would hurt the party's chances in premier House, Senate and governors' races.
The warnings come as Sanders shows new signs of strength in the first two states on the presidential primary calendar, backed by a dominant fundraising performance.
The Vermont senator has largely escaped close scrutiny over the last year as his rivals doubted the quirky 78-year-old's ability to win the nomination. But less than a month before Iowa's kickoff caucuses, the doubters are being forced to take Sanders seriously.
Sanders' camp says he has effected meaningful change in and out of Washington.