LACONIA, N.H. (Reuters) - Freshman New Hampshire legislator Gaby Grossman was surprised earlier this year to get a voicemail from U.S. Senator Elizabeth Warren, who had called to talk about her White House campaign.

FILE PHOTO: Democratic 2020 U.S. presidential candidate and U.S. Senator Elizabeth Warren (D-MA) speaks at a campaign town hall meeting at the University of New Hampshire in Durham, New Hampshire, U.S., October 30, 2019. REUTERS/Brian Snyder/File Photo

“She said: ‘Hey, just want to catch up and talk,’ and then gives her phone number to call her back,” said Grossman, who like other elected officials in the early primary voting state are used to hearing from Democratic presidential campaigns seeking their support - but not from the candidates themselves.

The state lawmaker endorsed Warren last month and still plays the voicemail for friends.

Warren’s direct outreach was a sign of her quiet efforts to woo party insiders and try to quell lingering concerns about her candidacy among the party’s establishment as the Massachusetts progressive has become a top contender for the Democratic nomination to take on Republican President Donald Trump in the November 2020 election.

Although Warren leads former Vice President Joe Biden in fundraising and is neck and neck with him in national opinion polls, she trails him and even other lower-polling, moderate rivals in major endorsements that traditionally signal a candidate’s strength in states with the first nominating contests.

She also still faces a major threat from U.S. Senator Bernie Sanders of Vermont, a friend and fellow liberal who despite a heart attack shows no signs of bowing out ahead of the rivals’ key showdown in the New Hampshire primary on Feb. 11.

Interviews with nearly a dozen Democratic insiders in New Hampshire show Warren is trying to close the gap by giving personal attention to lesser-known, yet still influential local leaders to secure their support.

She is using those conversations to set herself apart from Sanders, a political independent in the Senate. While she does not specifically reference him, Warren is telling Democrats that she unequivocally supports the party, the sources said.

One New Hampshire party official, who has yet to endorse, said Warren assured her in a one-on-one conversation that she is a “real Democrat.”

In New Hampshire this week, Warren reminded an audience she had campaigned for their U.S. senators, Maggie Hassan and Jeanne Shaheen, as well as 2016 presidential nominee Hillary Clinton, and she raised $11 million for Democrats and state parties during the 2018 congressional elections.

“Let me start by saying I am on this team and whoever is our Democratic nominee, I am in 100 percent,” Warren said. “I think this is important.”

TRAILING IN ENDORSEMENTS

Sanders rankled many Democrats when he did not share his donors list with the Democratic National Committee after his failed 2016 bid for the party’s presidential nomination.

As a result, the DNC asked 2020 Democratic candidates to sign a “loyalty pledge” that they would run and govern as Democrats, which Sanders did.

Questions persist for both Sanders and Warren about whether their uncompromising liberalism may alienate moderate Democrats and independents whose votes are crucial to beat Trump.

Although she won the backing of the Working Families Party, a progressive group with more than 50,000 members, Warren had the endorsement as of late October of just one fellow U.S. senator, Ed Markey, also from Massachusetts. Nine members of the U.S. House of Representatives have backed her campaign, along with one big-city mayor, Philadelphia’s Jim Kenney.

Biden had endorsements from five U.S. senators, 16 House members, two big-city mayors and three governors, according to the website FiveThirtyEight.

Warren also lagged Biden, Sanders and fellow Senators Kamala Harris and Cory Booker in overall endorsements from state legislators, although she has the most in Iowa, which hosts the first nominating contest, according to a tracker compiled by University of Houston professor Boris Shor.

Biden also is supported by New Hampshire’s popular Democratic former Governor John Lynch.

Warren’s campaign said it was focused on getting grassroots endorsements, such as those from community leaders, local officials and activists.

Terry Shumaker, a former U.S. ambassador for President Bill Clinton and prominent New Hampshire Democrat, said having the backing of local leaders with stature in their communities mattered in places like New Hampshire.

“Most people in New Hampshire put more stock in who the selectmen in their town are supporting. When they see a candidate’s yard sign in that person’s lawn, that probably gets more supporters than if their U.S. congressman endorsed this or that candidate,” said Shumaker, who has endorsed Biden.

Some of the behind-the-scenes work being done by Warren and her campaign could matter more when it comes time to vote, her supporters said.

Lisa DeMio, chairwoman of the Hampstead Democratic Committee, supports Warren personally, although DeMio will not endorse a 2020 primary candidate in an official capacity.

DeMio said Warren’s team - along with Booker’s - had sent a staffer to every monthly meeting held by a six-town coalition in a Republican-leaning area of New Hampshire since launching her campaign, showing it will leave no stone unturned.

“It’s a really well-run campaign,” DeMio said. “Their engagement and their strategy is, ‘let’s talk one-on-one over coffee.’”