The split between MassachusettsDemocratic establishment figures supporting former secretary of state Hillary Clinton and grass-roots activists swarming around US Senator Bernie Sanders of Vermont could leave party fissures that linger long after Tuesday’s primary.

Early voting in other states has revealed a national party torn between Clinton’s promised steady hand and Sanders’ more progressive goals, virtually ensuring a protracted nominating contest.

But perhaps nowhere is the Democratic divide clearer than in this state, long a Clinton redoubt, where the state’s elected officials have presented a monolithic front not seen in many other states. Ten of the state’s 11 representatives in Congress, three of its four Democratic constitutional officers, a long line of mayors, and a silent army of the state’s professional political class have all deployed on Clinton’s behalf.

If Clinton loses the March 1 primary or escapes with a narrow win, as recent polls suggest she could, the party establishment here risks backlash from left-leaning rank and file voters who back her opponent. A Sanders victory would leave the state’s Democratic political class looking out of step with its increasingly younger, progressive base and could, party strategists fear, leave some incumbents at risk of unusually contentious primary challenges.

“It may not be this year, but next year, the year after, those people are going to start running,’’ said Democratic strategist Scott Ferson, referring to younger activists. “And they don’t care about the order, or the regular rules. People are talking to me all the time about it.’’

Particularly in the state’s most left-leaning districts — areas like the Berkshires and cities like Cambridge — where Sanders is expected to perform well, the evident gap between elected incumbents and the activist base could usher in a new era for the Democratic Party.

“They’re still thinking institutionally and ‘Hillary Clinton is going to be the nominee and she’ll be elected president and everything is going to fall back into line,’ ’’ Ferson said of the big-name Democrats backing the front-runner. “But Bernie Sanders made plain that there is a change in Democratic progressive politics.’’

Democrats supporting Sanders say that some of their colleagues regret signing on with Clinton early in the race, when she looked like the runaway nominee.

“With a lot of elected officials, there is a sense of ‘I wish I didn’t endorse so early, because if I hadn’t, I would be with Bernie Sanders now. If I waited instead of going so early, today I would probably be with Bernie Sanders because he speaks to my beliefs and my values,’ ’’ said state Representative Michael J. Moran, a Brighton Democrat and one of the handful of state lawmakers who have endorsed Sanders.

Noting the preponderance of elected officials backing Clinton and polls showing a roughly even split among the primary electorate, state Senator Dan Wolf of Harwich, a Sanders supporter, said, “There’s some kind of disconnect with our constituents there. Whether there’s a political price to pay because of that remains to be seen.’’

“I think people should be accountable for those decisions in the political world,’’ he added.

A new poll suggests a close race statewide, with the edge to Clinton. The WBUR poll, released Friday morning, gave her 49 percent to Sanders’ 44 percent among likely primary voters, with a margin of error of plus or minus 4.9 percentage points.

Sanders partisans argue that traditional polling does not accurately depict the race because, like Donald Trump on the Republican side, the Vermonter has reshaped the electorate by drawing in atypical voters with his populist message.

“He’s putting his faith totally on the grass-roots workers and voters, which has allowed him to be competitive with the most establishment name in politics for the last 25 years, who has decided to go totally the other route,’’ said Paul Kirk, a former interim US senator from Massachusetts who has endorsed Sanders.

Sanders’ disruption of the party rankles some Clinton backers and loyal Democrats.

“He’s not a mainline Democrat,’’ said former state Senate president Therese Murray, who has backed both of Clinton’s presidential bids. “A lot of people that are coming out and voting for him are registering as Democrats, but they’re not really Democrats.’’

The dynamics are different than they were eight years ago, the last open Democratic presidential primary. In 2008, the state’s Democratic power structure split between Clinton and then-US Senator Barack Obama.

Its brightest stars — then-Senators Edward M. Kennedy and John F. Kerry, then-Governor Deval Patrick — broke for Obama, despite long ties to the Clintons. Meanwhile, down-ballot Democrats like then-Mayor Thomas M. Menino and much of the state’s US House delegation campaigned for Clinton.

This year, the state’s only prominent elected statewide Democrat not backing Clinton is US Senator Elizabeth Warren, whose hard line against Wall Street has endeared her to the national left and who has resisted getting involved in the presidential race.

Warren’s endorsement is one of the most elusive and prized in the country, and would instantly confer increased legitimacy for Sanders or enhance Clinton’s progressive bona fides. But it remains unclear when or whether she will decide.

While the elected official class is nearly monolithic on Clinton’s side, activists are more split along the lines of the 2008 primary — some believing that Clinton has earned the nomination and others hungry for an outsider like Sanders. Because Democratic primaries award their delegates proportionally, the more votes Sanders piles up, the greater share of the convention delegation will be filled out by his supporters.

That competition for a finite number of delegation seats means Democratic officeholders, activists, and donors will be squaring off against their own traditional allies.

“This reminds me so much [of] 2008 and the very real tensions that existed between the Clinton and Obama camps toward the end of that primary,’’ said Jesse Mermell, a Democratic State Committee member and a former top Patrick aide. Mermell now leads the Alliance for Business Leadership, but spoke on her individual views.

Despite “real overwhelming concern that it was going to be a real political liability’’ for the party that its leaders were so divided in 2008, the wounds healed in time for the general election, Mermell said.

This year, the fracture is less among various prominent Democrats, but between them and the party base, particularly its younger members.

The WBUR poll shows that voters trust Clinton and Sanders equally to improve the economy and create jobs, but, at a clip of more than 3 to 1, prefer Clinton to handle foreign policy challenges, while twice as many think Sanders would better address income inequality.

Sanders holds a wide lead among voters between the ages of 18 and 29, while Clinton does much better with those 60 or older.

The poll was conducted Sunday through Wednesday among 418 likely primary voters.

Jim O’Sullivan can be reached at jim.osullivan@globe.com. Follow him on Twitter at @JOSreports.