Politics in Democrat-dominated Montgomery County can resemble a football game played strictly between the 40-yard lines. In primary season, candidates scuffle to distinguish their left-of-center approach from opponents who are, by and large, like-minded.

This year’s field of candidates for the four contested district seats on the County Council all want mass transit, robust funding of schools, affordable housing and environmentally sustainable growth.

They favor programs for at-risk youths and a more muscular presence at the State House in Annapolis to bring additional dollars home.

There are differences, but mostly of emphasis — along with style, temperament and life experience. The candidates include a family therapist, a community organizer, a state delegate, a Board of Education member, two former Marines and a bunch of lawyers.

Here is a summary of the races on the ballot in Tuesday’s Democratic primaries:

District 1

Dickerson, Potomac, Bethesda, Chevy Chase

Two-term incumbent Roger Berliner faces a challenge from Duchy Trachtenberg, a former at-large colleague in this western Montgomery district, which contains some of country’s wealthiest communities.

In her previous council term, Trachtenberg successfully sponsored legislation banning trans fat from food sold in county restaurants and barring discrimination against transgender residents. Trachtenberg, a family therapist, was a force behind the creation of the Montgomery County Family Justice Center, which supports victims of domestic violence and their families.

Elected in 2006 with labor backing, Trachtenberg alienated unions during the recession by supporting cuts in cost-of-living increases and tightening police disability-retirement regulations. They happily worked for her defeat in 2010.

Trachtenberg, 60, expressed remorse for some of her votes and won back the support of United Food and Commercial Workers Local 1994, which represents non-uniformed county workers. Once a “slow growth” proponent, she won backing this time from developers unhappy with Berliner’s role in limiting construction in the Ten Mile Creek watershed. But some of her support from developers has since fallen away.

Trachtenberg said Berliner has been part of a council culture of finger-pointing and backbiting that has hampered its effectiveness. One of her mailings to District 1 voters shows two children sticking out their tongues at each other to make the point. “We teach our school kids not to fight . . . why haven’t politicians gotten the message?” the caption says.

Berliner, 63, an environmental lawyer, said he is “running on my record,” which includes passage of nine bills to reduce the county’s carbon footprint and promote sustainability. He also led county efforts to press Pepco, the electric utility, and the Washington Suburban Sanitary Commission, the bicounty water and sewer agency, for better performance and more accountability. As chairman of the council’s transportation and environment committee, he was a key player in shepherding a plan for a bus rapid-transit network.

Trachtenberg has accused Berliner of a “double standard” because he voted for a 28 percent council pay increase last year while opposing a provision to index the county’s minimum wage to the rate of inflation. Her mailing says Berliner voted a pay increase “for himself,” which is not quite accurate.

Berliner joined the council majority in an 8-to-1 vote to raise members’ pay to $136,258 by 2017. But the increase applies to the council that will be seated after the November general election. (Trachtenberg said, if elected, she will donate the raise to the Family Justice Center she helped found.) Berliner also supported passage of the bill raising the county’s minimum wage to $11.50 an hour by 2017. The measure did not include indexing.

The winner of the District 1 primary will face Republican Jim Kirkland, who was unopposed for the nomination, in November.

District 2

Germantown, Clarksburg, Boyds, Damascus

Council President Craig Rice (D-Upcounty) said transportation and economic development are the major issues in this fast-growing area. “Economic development is a very big deal for the Upcounty,” said Rice, 41, a former state delegate seeking a second council term. He fought a losing battle to secure council approval of a retail and office development by the Peterson Cos. near the site of Clarksburg Town Center.

Rice faces a long-shot challenge from Neda Bolourian, a lawyer and first-time candidate who has raised less than $4,000. Bolourian said she would work to roll back the council pay raise, which she called “outright offensive.”

“I work every day, and I understand what it’s like to live in this county paycheck to paycheck,” said Bolourian, 32, the daughter of Iranian immigrants.

Bolourian, who works in Bethesda, said she would lower property taxes and raise additional revenue by legalizing, regulating and taxing marijuana — an issue that is under the state’s jurisdiction, not the county’s.

The winner will face Dick Jurgena, unopposed for the GOP nomination, in November.

District 3

Rockville, Gaithersburg, Leisure World

There are four contenders for this central Montgomery seat, held for the past 16 years by Phil Andrews, who is running for county executive: Derwood grant writer and business consultant Guled Kassim, Gaithersburg Mayor Sidney Katz, Rockville City Council member Tom Moore and Gaithersburg City Council member Ryan Spiegel.

Katz, 64, said he has 36 years in Gaithersburg government, 20 on the council and 16 as mayor, along with private-sector experience. Wolfson’s department store, which he recently closed, was started by his grandparents in 1918.

As former president of the Maryland Municipal League, Katz said, he has “friends across the state” who can help bolster Montgomery’s position in Annapolis.

Spiegel, 35, a lawyer and Gaithersburg council member since 2007, said affordable housing and green development are among his priorities. He said he also brings a more rounded skill set to the table.

“Some folks are good at building relationships and being well liked, but they’re not the ones who necessarily generate innovative policy ideas,” he said. “The best legislator is the one who can do both of those things.”

Moore, 46, a lawyer and former journalist, said his background in helping to run the county’s largest and most complex municipality gives him the edge. Closing the achievement gap in county schools requires widening economic opportunity, he said, by using transit to link neighborhoods with good jobs.

To fix the schools, Moore said, “we have to fix our families.”

Kassim, 39, a Somalian-born former Marine, said Katz, Spiegel and Moore have had years in office among them to address such issues as road congestion. Now, he said, fresh energy is needed. “At the end of the day, a lot of people have lost faith in local government,” he said.

No Republican nominee is running in the district.

District 5

Silver Spring, Takoma Park, White Oak, Burtonsville

This district along the county’s eastern edge is the heart of the new “majority-minority” Montgomery. Sixty-two percent of its residents are black, Hispanic or Asian. It also contains the greatest economic disparities: the revitalized downtown Silver Spring and the job-and-transportation poor stretches along New Hampshire Avenue and Briggs Chaney Road.

Board of Education member Christopher Barclay, former CNN producer Evan Glass, Del. Tom Hucker (D-Montgomery), community organizer Terrill North and nonprofit founder Jeffrey Thames are vying for the seat vacated this year by Valerie Ervin. (A council-appointed interim member, Cherri Branson, is not running.) Each claims to be the one best suited to meeting the manifest needs of the diverse district.

Ervin, the council’s first African American woman, declared District 5 a “legacy seat” that should continue to be represented by a person of color. She threw her support behind Barclay, who was also backed by the Montgomery teachers union and several council incumbents.

Barclay’s labor endorsements fell away this month after reports of unauthorized expenses on board-issued credit cards. But he said his school system experience still gives him the best grounding in issues that affect working and poor families.

“We’ve got to focus on supports outside the classroom that have an impact on kids and the community,” said Barclay, who is 53. He wants a workforce development center in the eastern part of the county and says school computer centers should be open after hours to help immigrants learn English online.

Hucker, 47, a two-term state delegate, is campaigning as the race’s only experienced legislator, touting a long list of measures he helped pass. He said his deep contacts in Annapolis are a must for a county that needs more support from the state.

“The last thing we want to do is to send a perfect stranger to meet with state agencies,” Hucker said. He said he wants high-quality preschool for all 3- and 4-year olds and rigorous enforcement of the county’s new minimum wage law.

Glass, 37, chairs the Silver Spring Citizens Advisory Board, which is appointed by the county executive. He said his work with tenant and neighborhood groups makes him the contest’s genuine local leader.

He said would push for significant upgrades in county bus service while residents wait for big-ticket improvements such as the Purple Line and bus rapid transit. He also proposes to end Montgomery’s monopoly over alcohol distribution.

North, 38, a former congressional staffer and community organizer, leads a mentorship program for at-risk youths in Silver Spring and Takoma Park. He said he would focus on expanding civic participation and economic empowerment.

“I have not focused on my relationships with Annapolis or developers or unions. I do real work in actual communities,” he said.

Thames, 35, is a former Marine and founder of the nonprofit Hope Restored. He said he would advocate for schools, business incubators, safe streets and efforts to reduce exposure to Lyme disease in parks and open spaces.

No Republican nominee is running in the district.