State Sen. Jamie Raskin, during a debate for the Maryland 8th Congressional District seat at the Aspen Hill Library last month. (Evelyn Hockstein for The Washington Post)

Here comes David Trone, again. Walking the suburban Maryland farm that his father lost. Chatting up employees at one of his big-box wine stores. Behind the desk in his modest office.

His self-financed wave of television, radio and digital ads has been hard to miss for voters in Maryland’s 8th Congressional District. It’s the leading edge of the Potomac millionaire’s vow to spend whatever it takes to win the April 26 Democratic primary.

Trone’s torrent of cash is a challenge for the eight other Democrats in the race, especially the two candidates regarded as front-runners: State Sen. Jamie B. Raskin (D-Montgomery) and former Marriott executive and news anchor Kathleen Matthews. While the next campaign finance reports aren’t due until shortly before the primary, Democratic insiders estimate that Trone, who entered the race on Jan. 27, has already spent more than $2 million on advertising, polling, direct mail and staff. That’s more than either Raskin ($1.3 million) or Matthews ($1.5 million) have raised since last spring.

Trone, Raskin and Matthews all present a progressive message to voters in the liberal 8th, the mushroom-shaped district that stretches from Takoma Park to the Pennsylvania line and has been held since 2003 by Rep. Chris Van Hollen (D-Md.), who is running for the U.S. Senate.

Democratic candidate Kathleen Matthews is seen during a debate for the Maryland 8th Congressional District seat at the Aspen Hill Library in Aspen Hill, Md. (Evelyn Hockstein for The Washington Post)

They pledge to attack climate change and income inequality, reduce gun violence and protect abortion rights. They want to raise the minimum wage, make college more affordable and establish a path to citizenship for immigrants.

With two months until the start of early voting, the three — who met with other Democratic hopefuls for a debate Sunday at Leisure World — are pursuing different paths to victory. Call it incumbency vs. gender vs. entrepreneurial success.

Raskin, 53, is trying to build on the grass-roots organization that’s lifted him to three election victories in his Silver Spring-Takoma Park senatorial district. He’s running as a “true-blue” progressive, pointing to major roles he played in passage of Maryland’s 2013 marriage equality legislation and repeal of the death penalty.

An outspoken critic of runaway campaign spending, Raskin says he will almost certainly be outspent— by Matthews as well as Trone. “Public office is something you earn, not something you buy,” he said in a recent online fundraising pitch.

For Matthews, 62, Trone’s emergence could diminish her appeal to moderates in the northern and western reaches of the district. But it also sharpens what is already an advantage: running against seven men — and one other woman — in a district where women are 60 percent of the Democratic primary electorate.

She often reminds audiences that Sen. Barbara A. Mikulski’s retirement and the departure from Congress of Rep. Donna F. Edwards, who is running against Van Hollen in the senatorial primary, could leave Maryland with an all-male House delegation.

Matthews tries to offset her lack of legislative experience by talking up her 30 years as a television reporter and anchor, which she says afforded her first-hand experience with the country’s biggest issues. She emphasizes her decade as an executive at Marriott, where she said she helped broaden the company’s environmental consciousness and made it more hospitable for LGBT employees.

“I always believed that the way to win was to get in early, let the voters see me up close,” Matthews said. “I think having a self-funded candidate jump in three months before the election doesn’t change that.”

Trone, 60, and his brother Robert built Total Wine & More into the nation’s largest privately held retailer of beer, wine and spirits, with more than 130 stores in 18 states. He’s a prodigious national Democratic donor — and has been generous to both parties at the state level, where his business is regulated.

He is fashioning himself as a more civil, Democratic version of Republican presidential front-runner Donald Trump: a plain-speaking, answers-to-no-one businessman pursuing a liberal — rather than a conservative — agenda. Trone has taken several shots at Trump already, criticizing the million-dollar loan the Republican received from his father as a young man and his hard-line stance on immigration.

“Trump makes me livid,” Trone said in an interview. “He’s insulting to his opponents. He’s antagonistic to women. People need to see that business candidates are open and supportive.”

Trone said his career has given him broad experience in working with both Democratic and Republican officeholders. He offers some un­or­tho­dox ideas, such as offering basic banking services at post offices to help low-income families avoid payday lending and other predatory financial practices. He wants to “hold colleges accountable” for their graduation rates (although he doesn’t say exactly how) and favors loan forgiveness for students who commit to five years of public service after graduation.

His campaign is modeled in some ways after that of Rep. John Delaney (D-Md.), another wealthy, self-funded Potomac Democrat. Delaney spent $2.3 million of his own money in 2012 to knock off the favored Democratic primary candidate in Maryland’s 6th District, State Sen. Robert J. Garagiola, and then Rep. Roscoe Bartlett (R), a 20-year incumbent.

But the 8th is more liberal than the 6th, and the field of candidates stronger. Moreover, the success rate for self-funders is relatively low. The Center for Responsive Politics found that fewer than 15 percent of self-funded congressional candidates — defined as those who spent at least $500,000 of their own money — won their races between 2002 and 2012. In Maryland’s 2006 senatorial primary, Democrat Josh Rales, another Potomac businessman, spent $5 million of his own money and captured just over 5 percent of the vote.

The rest of this year’s 8th district Democratic hopefuls, with far less money in the bank, are having to grab attention any way they can.

Will Jawando, a 33-year-old African American, is basing his appeal on demographics and Washington experience. “Congress is not Annapolis. Tea Party Republicans are not Maryland Republicans,” said Jawando, a former Obama Senate and White House aide. “Who represents the great diversity of our community?”

Del. Kumar P. Barve (D-Montgomery), 57, the senior legislator in the field, is serving his seventh term in the House of Delegates, including a long stint (2003-14) as majority leader. Last year, he led the move to pass a moratorium on fracking. An accountant by training, he emphasizes his business experience — he’s CFO of a Rockville environmental cleanup company — and says he wants more education and training for what he calls “middle-skills jobs,” such as utility line workers.

Del. Ana Sol-Gutierrez (D-Montgomery), 74, has made her life her message: immigrant, chemist and systems engineer, senior Transportation Department appointee in the Clinton administration, first Salvadoran American to win public office in the United States with her election to the Montgomery County Board of Education in 1990. Like Matthews, the four-term state lawmaker says Congress needs more women at the table.

Joel Rubin, 44, is a former congressional liaison to the State Department and co-founder of J Street, the liberal advocacy group that promotes a two-state solution to the Israeli-Palestinian conflict.

David Anderson, 49, an executive for a nonprofit that raises money for college scholarships and internships, says he wants to see family and tax policy changed to provide more support for stay-at-home mothers.

A ninth candidate, Dan Bolling, entered his name just before the Feb. 3 filing deadline. A retired biotech executive who lives in Bethesda, Bolling, 65, ran for Congress in Indiana in 2012. He favors changes to Congress’s committee and leadership structure that he says would make it more functional.

On the Republican side, five candidates are vying for the nomination, including three who signed up just before the filing deadline: Dan Cox, Jeffrey Jones and Liz Matory, who had originally filed as an independent. None have the name recognition or financial support wielded by the Democratic front-runners.