Quentin Palfrey started in early July, dialing political strategists and top labor union officials, fund-raisers, and members of Congress, sounding out potential support for his bid to become the Democratic nominee for lieutenant governor in 2018.

He quickly learned he was just about the only one.

“I was a little surprised,’’ said Palfrey, a former Obama White House aide and Weston resident. “When you have a bunch of conversations and people tell you that you’re the first person who’s called them . . . maybe you’re filling a need.’’

In the age of President Trump, when political passions burn hot, internal party dynamics and external forces have limited career opportunities for younger Democrats in Massachusetts. And since few of the state’s top Democrats are moving anywhere, it’s hard for other political aspirants to move up.

“We hold a lot of the high offices, but I think there needs to be a system in place on how we continue to move talent through,’’ Mayor Martin J. Walsh, who spent nearly two decades in the Massachusetts House before the city’s top job opened in 2013, said in an interview last week.

“If the Democratic Party wants to take control of the governor’s office, or make sure we keep control of all the congressional offices, I think we need to do a better job of organizing within the different parts of the state.’’

Analysts attribute the recent stagnation to a handful of factors.

An all-Democrat congressional delegation dampens the enthusiasm of ambitious would-be challengers, who win few points within the party for taking on an incumbent.

And Republican Governor Charlie Baker’s popularity has deterred some high-profile possible candidates from taking a shot at the governorship.

Baker’s standing is such, party insiders say, that it partly explains Palfrey’s lack of rivals, too. Not only has the first-term governor discouraged competitors for the top job, but even those seeking to join a ticket against him are thinking twice.

Third, among party insiders, there is an underlying concern that, nearly three years after Deval Patrick left the governor’s office, a power vacuum remains. There is no obvious elected leader among Democrats who, working with the state leaders, is helping to direct promising lower-tier candidates toward the right races.

Looking ahead to the 2018 elections, all but one of the state’s nine US representatives are planning to keep their posts, and the state’s senior US senator, Elizabeth Warren, is running for reelection. The Democrats who hold four of the state’s six constitutional offices have all signaled they plan to stay put, and it’s rare for party members to oppose one of their own in a primary.

It’s a sharp contrast with the Republican Party, where relative newcomers are encouraged to take on the state’s all-Democrat congressional delegation or seek statewide office — albeit with limited success in recent years. And there are plenty of seats for the GOP, with their tiny numbers here, to gun for without worrying about intraparty tension.

But for Democrats, it’s a far cry from just a few years ago. Patrick was not seeking a third term, John F. Kerry left the Senate to become secretary of state and, months later, Boston Mayor Thomas M. Menino said he would not seek another term.

The floodgates opened, allowing several Democrats — Senator Edward J. Markey, Representative Katherine Clark, and Walsh — to ascend to their current roles. Just a year before, Joseph P. Kennedy III won the congressional seat Barney Frank had held for 32 years.

With Patrick and his team relinquishing the party’s levers of power, Walsh and then-party chair Thomas McGee, a Lynn Democrat, convened strategy meetings among the state party’s top figures as far back as early 2015, but those sessions have since subsided.

In the past, similar leadership roles — where an elected powerbroker has wielded outsized influence over party ideology and personnel — have been filled by governors, Boston mayors, and US senators. It’s a role Edward M. Kennedy played for years. But both Warren and Markey appear more focused on Washington and national affairs.

“[Warren] has got a national constituency that she’s concerned about,’’ said University of Massachusetts political science professor Ray La Raja.

Back at home, some party leaders and strategists have fretted that none of the Democratic candidates for governor has the status to give Baker a fight. The three announced contenders — Jay Gonzalez, Setti Warren, and Bob Massie — have thus far failed to excite party activists.

If a rung high on the ladder opened up, the state has a crop of young Democratic stars. In Congress, Clark, Seth Moulton, and Joseph P. Kennedy III have all built strong profiles within the party. As a second-term representative, Moulton has sparked speculation that he could run for president in three years, and some Democrats wonder privately whether he would challenge Markey in 2020.

Attorney General Maura Healey, too, has cultivated national attention by confronting Trump on legal grounds.

But Democrats couldn’t persuade any of them to take on the popular GOP governor.

“They didn’t put anybody up to really challenge Baker,’’ said La Raja. “The party organization itself is not really strong in this state. They’re not recruiting anybody, and it’s a big risk to take on Baker. But a strong party would say, ‘Hey, we’re taking them on anyway, to get our message heard.’ ’’

Further, many had expected that a Hillary Clinton victory in last year’s presidential election would have resulted in federal appointments for many state Democrats that would have eased the logjam.

Representative Niki Tsongas’s announcement this month that she would step down at the end of her term created some volatility, flushing out elected Democrats and other party heavyweights. But Warren’s plans for a second term and the widespread expectation that Markey, too, will seek another term have further crimped the party pipeline.

Before Moulton knocked off a long-term incumbent in 2014, it had been over 20 years since a Democratic representative lost a primary here.

Some in the party point out the virtues of incumbency.

“When you face what we’re facing federally now, with Trump trying to cut programs and change things, you do want people who know how to get it done, how to challenge things in courts, how to make sure that the state government knows how to fill in the gaps,’’ said Andrea Cabral, a former state public safety chief and now a WGBH radio host.

But in recent years, a string of young Democratic legislators widely seen as ambitious for higher office has stepped out of the electoral jet stream entirely, often for more lucrative careers.

Last week, state Senator Jen Flanagan, viewed as an eventual candidate for one of the chamber’s top posts, accepted a job as commissioner on the state’s new cannabis policy panel. Her former colleague Ben Downing, also marked for ascent, left earlier this year for the private sector.

State Democratic Party chairman Gus Bickford calls the logjam “a good problem to have,’’ adding, “I think it’s a very healthy bunch of Democratic elected officials who are in a lot of great places.’’

Bickford said the opposition to Trump has stirred up unprecedented grassroots intensity, and expects it to produce a string of first-time candidates across government in next year’s statewide election.

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