Democrats are sounding the alarm. In the days since State Sen. Doug Mastriano decisively clinched the Republican nomination for governor, progressive groups, labor unions, and liberal elected officials have framed the midterm election in existential terms.

One of the state’s largest unions told members Mastriano would end “union rights as we know them.”

State party officials launched a bus tour called “Protect Our Rights” that’s focused on threats to abortion access.

And on Monday, Attorney General Josh Shapiro, the Democratic nominee, wrote in a fund-raising email that Mastriano is “the most extreme candidate running for governor in the country,” and asked for donations to help “turn out every voter we can.”

Pennsylvania Democrats say they’re plotting expansive campaigns to drive general election turnout — and hoping Mastriano’s candidacy will be a motivating force.

While midterms are typically more low-profile than presidential elections, some unions and progressive organizations say they’re sketching out grassroots operations in Pennsylvania that rival the months leading up to November 2020 in size and scope. Some have already started canvassing general election voters.

“We need to have the kind of operation we had in 2020 if we’re going to win,” said Emiliano Rodriguez, an organizer with Unite Here Local 274, which represents service workers and knocked on more than 300,000 Philadelphia doors in 2020 in support of Joe Biden. “People are under a ton of pressure and don’t feel great about the state of our lives. Not voting can be a very natural thing to do. That’s where we think we really need to focus.”

This, of course, isn’t 2020, and most political observers predict 2022 will be nightmarish for Democrats. The party that holds the White House almost always performs poorly in midterms, and Biden’s approval rating has tanked amid high inflation and a stalled domestic agenda.

The GOP, meanwhile, has momentum. Strong performances by Republicans in New Jersey and Virginia last year portend dissatisfaction among the electorate. Unofficial returns from last week’s primary election in Pennsylvania show Republican turnout nearly doubled compared with 2018. And polling shows only about a third of Democrats think the country is headed in the right direction, which strategists say could lead to low energy and weak turnout.

But Democrats in Pennsylvania say they think the state could buck that conventional wisdom as voters consider a Republican nominee who wants to ban abortion, was subpoenaed by the committee investigating the Jan. 6 Capitol attack, and has associated with people who promote the QAnon conspiracy theory.

“Particularly with the governor’s race, where there is such an extremist running, you will see Democratic base voters trying to turn out against that,” said Gabe Morgan, vice president and state director of 32BJ of the Service Employees International Union. “I also think you will see a lot of folks who are not interested in more crazy.”

And Democrats say they’re already thinking through post-election scenarios involving Mastriano, who has made baseless claims about the validity of mail ballots cast in 2020 and led efforts in Pennsylvania to overturn former President Donald Trump’s defeat.

Jason Henry, executive director of the Pennsylvania Democratic Party, pledged “one of the largest grassroots operations in the country.”

“We recognize that we can’t just rest on our laurels,” he said. “We’re going to make our case to every voter in every corner of the commonwealth — not just what we’re going to do, but we’re also going to point out what the other side will do.”

» READ MORE: Pa. Democrats are rallying behind abortion rights as they look for a new midterm election message

There have been some signs of grassroots energy on the left since Mastriano’s nomination. In the 24 hours after the primary election — which was uncontested on the Democratic side — Shapiro’s campaign added to its significant war chest, raising $200,000 online, which it said was more than triple its previous best day.

Still, Mastriano is formidable. He handily won the crowded primary race and showed he has broader support in the GOP than even many Republicans anticipated. Voters also will likely be inundated with ads in the race for Pennsylvania’s open Senate seat, which could tip control of chamber.

Political observers say Mastriano’s candidacy could be a motivator. Alison Dagnes, a political science professor at Shippensburg University, said getting voters to turn out is about emotion — “fear, anger, or love.”

“It’s not that anyone’s in love with Josh Shapiro,” she said. “They are petrified of what would happen if somebody who is somber and clearly very dedicated is not in that office.”

Shapiro hasn’t avoided scrutiny from the left. Some were dismayed his campaign ran ads portraying Mastriano as ultra-conservative, saying it boosted the most extreme candidate on a gamble that Shapiro can beat him. (Shapiro said Sunday in a CNN interview that Mastriano was already leading the field and “what we did was start the general election campaign.”)

Others have questioned Shapiro’s proposal to send a $250 gas tax rebate to car owners, saying it incentivizes car ownership over more environmentally friendly modes of transportation.

But even uber-progressive organizations that might have ideological differences with the more moderate Shapiro have committed to pouring money into the state.

Maurice Mitchell, national director for the labor-aligned Working Families Party — which ran one of Philadelphia’s most visible voter engagement campaigns in 2020 — said the races in Pennsylvania are a top priority and the group will be investing “significant resources.”

“We’ll be raising and spending millions of dollars and putting that into the field and mobilizing thousands of volunteers,” he said, adding that its team is working up “every type of voter content you could imagine.”

But Mitchell cautioned Democrats against centering their message on the opponent, saying, “Scare tactics alone are insufficient.”

» READ MORE: Pennsylvania Republicans tried to stop Doug Mastriano. But first they followed him.

Duncan Hopkins, a 25-year-old organizer with the progressive political group Lancaster Stands Up, agreed, saying Democrats can’t “just say, ‘Look at the other guy.’”

“It’s really hard right now to get people engaged,” he said. “There’s an overwhelming view that our government isn’t working for us.”

Hopkins said he voted for Biden but feels Democrats in Washington have made less progress on issues like climate and immigration than he’d have hoped. If a more progressive Democrat had run against Shapiro, he said, he probably would have voted for that person.

And yet, he plans to do everything he can to get Shapiro elected.

“It’s very clear what Doug Mastriano will attempt to do if he’s elected governor,” Hopkins said. “And at the end of the day, that cannot happen. It is on all of us.”

Staff writers Sean Collins Walsh and Julia Terruso contributed to this article.