Senate Democrats are criticizing Bernie Sanders platform as naive, taking exception to his criticism of Clinton as a fake progressive. | AP Photo Sanders under fire from Senate Democrats After ignoring him for months, his colleagues in the Capitol are taking aim at Sanders and defending Hillary Clinton.

Bernie Sanders' Democratic Senate colleagues have pretty much left him alone throughout his presidential run. Most of them saw his campaign as quirky and idealistic, certainly no threat to the candidate they overwhelmingly back, Hillary Clinton.

But now, after his near-upset in Iowa and an expected victory next week in New Hampshire, it's beginning to look like open season on Sanders for Senate Democrats.


They're criticizing his platform as naive, taking exception to his criticism of Clinton as a fake progressive, and imploring the media to put the Vermont independent and self-described democratic socialist under the microscope.

"You need to start asking him questions about his plans and his background,” said Sen. Jeanne Shaheen (D-N.H.). Ask “how he’s going to address foreign policy and national security, how he’s going to pay for his higher education and health care proposals. There are a lot of unanswered questions.”

Shaheen has begun making that argument in her home state as New Hampshire prepares for another referendum between Clinton and Sanders. And she's being joined by a growing group of Sanders critics after he made the claim Wednesday, on Twitter and the campaign trail, that Clinton is a progressive “some days, yes. Other days she announces she is a moderate."

“Hillary Clinton is a progressive and I don’t think any other progressive gets to judge … and be the gatekeeper of progressivism,” said Sen. Brian Schatz (D-Hawaii), who won a 2014 Senate primary running as the more liberal candidate. “We need to remember who our real adversary is, and that’s the tea party and what they’ve done to the country.”

Some went further, saying Sanders, who caucuses with Democrats but identifies as independent, isn't really a Democrat..

"Hillary's a progressive in the way she views the issues every day," said liberal Sen. Barbara Boxer (D-Calif.). “Bernie’s a Democrat some days. And that’s a fact with evidence.”

The number of Democratic senators willing to insert themselves in the increasingly divisive contest for the Democratic contest remains slim despite the fact that 39 of the caucus’s 46 members have endorsed Clinton. But it is growing.

Even members of the Congressional Progressive Caucus, of which Sanders is the only Senate member, bristled at his attempts to label Clinton.

"I certainly think she is progressive enough. One could ask progressive enough for what?" said Rep. Karen Bass (D-Calif.). "Although there are a lot of positions that Senator Sanders has that I agree with in theory, I also believe that we are not going to get [them] done in this current political environment."

For months Sen. Claire McCaskill (D-Mo.) seemed to be the only Democratic senator who would say what much of the caucus was thinking: That Sanders is unelectable in a general election and has not been fully vetted by the voters. Now, she says, more and more lawmakers will be speaking out.

The Missouri Democrat, who found herself on Clinton's bad side after endorsing President Barack Obama in 2008, says her colleagues are not happy that they keep getting lumped into the "establishment" whenever Sanders dings Clinton for her long Democratic Party ties and deep party backing.

“All of us are laughing going like, ‘How did we become establishment?’” McCaskill said. “I’ve been fighting the establishment my whole life. It feels weird that they’re dismissing all of the senators that are supporting Hillary Clinton by kind of lumping us into some category that most of us find distressing and unfair.”

Sen. Tammy Baldwin (D-Wis.) said the backing of 13 female senators shows that Clinton's support isn't “establishment." After all, she said, they are 13 of just 46 women senators to have served in the history of the chamber, a case Baldwin made to Iowa voters last month while campaigning for Clinton.

The backlash to Sanders’ Wednesday comments and his “establishment” jabs coincides with more targeted criticisms of the Vermont independent. Prominent immigration activist Astrid Silva endorsed Clinton over Sanders this week, prompting a Sanders spokeswoman to dismiss the endorsement as little other than a “press hit.”

That raised the eyebrows of Senate Minority Leader Harry Reid (D-Nev.), who has remained neutral in the primary but felt compelled to respond.

“Nobody needs to attack her, this little girl that came across the river in a boat with a doll and rosary beads. I’m not going to let anybody mess with her, no matter who it is. Very personal for me, nobody will mess with Astrid. I’ll fight back,” Reid said in an interview.

Then there’s foreign policy, where Sanders has said he would seek to normalize relations with Iran as much as he can. This strikes many colleagues as unrealistic.

“You're never going to have a normal relationship ... they’re openly hostile to us, they openly finance attacks against Americans," said Sen. Ben Cardin (D-Md.), the top Democrat on the Foreign Relations Committee and a Clinton backer.

Despite the sharper criticism from some lawmakers, the Democratic caucus is split over how hard to go after Sanders, if at all. Many lawmakers believe that attacking Sanders could divide the party at a time when unity against Republicans is needed.

“I don’t plan on pointing out negative things about Bernie,” said Sen. Sherrod Brown (D-Ohio).

Yet the fact that Sanders has not received a single endorsement from his Senate colleagues — and has just two House endorsements — speaks volumes, Clinton supporters say. From the liberal Brown to the moderate Joe Manchin, the caucus is nearly united for Clinton.

Sanders supporters want "to dismiss the fact that none of his colleagues have endorsed him, but you can’t,” McCaskill said. “He hasn’t had the ability to get consensus or lead people.”

Lauren French contributed to this report.