“My feeling is that I’m still not sure who the best candidate to run against Trump is,” said Sen. Chris Murphy (D-Conn.), one of the party’s up-and-coming senators. “I always thought the primary was a way of sorting out the most battle-ready candidate. And until we at least have one election [in Iowa], I don’t think we can really know who is ready.”

“I’ll make an endorsement when my gut tells me I know who the right person is. It’s an intuition thing. And I’ll know it when I know,” said Sen. Tim Kaine (D-Va.), the 2016 vice presidential nominee. “My gut told me really early that Obama was the right guy and my gut told me really early that Hillary is the right person. And I’m just not there yet.”

The decision to avoid playing in the primaries reflects the awkward nature of this particular campaign, with six Democratic senators still running. Five senators also ran in 2008, but the caucus has become averse to the kind of brutal battles of the past. Senators chose sides between Hillary Clinton and Barack Obama in the 2008 race, creating wounds that festered for years.

Endorsements at this stage could reassure voters that the establishment believes Warren isn’t too far left or help stabilize the wobbly Biden candidacy. But if an endorsement backfires and creates dissension with the rest of the field, then “you build enemies for life,” said Sen. Jon Tester (D-Mont.). He predicted many senators will wait for the convention before choosing between candidates.

Senate Minority Whip Dick Durbin (D-Ill.) said he would “never say never” to making an endorsement but indicated he wouldn’t want to rock his own parochial politics. After all, he wants to be re-elected as whip in the next Congress and snubbing five or six senators by making an endorsement wouldn’t be the way to do it.

“Right now, I’m thinking I won’t. But I don’t know. I’m not clear at this point who I think is the strongest,” said Sen. Debbie Stabenow (D-Mich), who endorsed Clinton early in both 2008 and 2016. “Unless I feel very strongly about a person, I think there may be a more appropriate role to play to bring everybody together afterwards.”

Others are firmer in their neutrality despite the heft they could bring in critical states. Sen. Tammy Baldwin (D-Wis.) said she’s “staying out” as her state prepares to host the convention, though she is offering guidance to candidates about how to win Wisconsin after her 2018 re-election bid.

Iowa currently doesn’t have any Democratic senators, so New Hampshire’s two Democratic senators could be kingmakers as the highest-ranking party officials in the two early states. But neither seems eager to make waves.

Sen. Jeanne Shaheen, a former governor of New Hampshire, said she will not endorse in the primary while she’s running for her own reelection, “period.” Sen. Maggie Hassan, who supported Clinton in 2016 while Hassan ran for her first Senate term, hasn’t closed the door entirely this time around.

“I really haven’t made a decision about whether I’m going to endorse,” she said. “It’s early and I think that the people of New Hampshire are continuing to do what they always do, which is really just vet people.”

Sen. Gary Peters, who is up for reelection in the swing state of Michigan, also is holding back for now.

“I’m not making one, but I would never shut the door [and say] that I’ll never do that,” he said. “It’s possible I’ll make an endorsement when we get down for a smaller field.”

Ten senators have backed 2020 contenders so far, but it’s mostly to show some home-state love, with Democrats like Tina Smith of Minnesota and Robert Menendez of New Jersey endorsing Amy Klobuchar and Cory Booker, respectively. The only exception is Biden, who is supported by five senators.

Tester was the most recent senator to offer an endorsement, backing Montana Gov. Steve Bullock back in June. That leaves 31 unaffiliated Democratic Caucus members, while House members have continued offering a trickle of endorsements over the past five months.

Democrats’ broadly neutral stance echoes the GOP’s chaotic 2016 race, when the party refused to coalesce behind anyone, and Trump burst into a lead he never relinquished. Some senators made efforts to back Marco Rubio or Ted Cruz to stop Trump, but they came too late to make a difference, or perhaps wouldn’t have ever mattered much at all in an anti-establishment moment. Then Trump won the general election anyway.

The Democratic Party has overhauled its superdelegate process after overwhelming support for Clinton's 2016 campaign from the establishment — including a multitude of senators — raised ire from the left. In 2020, senators still have some sway on the electoral process that could prove critical if the race goes down to the wire in Milwaukee. Superdelegates can’t vote in the first ballot at the convention but can weigh in during future rounds.

Sen. Joe Manchin (D-W.Va.) said the key moment when senators and governors could make a decisive push for a single candidate won't happen until at least Nevada or South Carolina. Moving now would be counterproductive, he said.

“I want to work with these people. Other senators in the caucus think the same as I think. These are all friends that they know, whether they agree or disagree, whether they would vote for them or not, they’re still friends,” Manchin said. “And you don’t publicly do that to your friends.”

Not everyone is scared of offending. After flirting with his own presidential run, Sen. Sherrod Brown (D-Ohio) indicated he could give someone the nod before Iowa.

But timing isn’t his top priority. Like Murphy and Kaine, Brown said his endorsement doesn’t hinge on anything other than who can win and govern.

“I want to just see what they are doing, how they sound, how they look, how they handle pressure. I’m in absolutely no hurry,” Brown said. “I want the candidate who will be the best president and the best one to win will likely be the one that will be the best president. They can prove themselves that way.”