This story has been updated to reflect the June 15 campaign finance filings.

George L. Leventhal has a long list of political bona fides. He was a legislative director for five-term U.S. senator Barbara A. Mikulski (D-Md.). He chaired the Montgomery County Democratic Central Committee. And he is finishing his fourth — and, thanks to term limits, final — stint on the Montgomery County Council.

“I worked my way up through the Democratic Party structure,” said Leventhal, who proffers himself as the county executive candidate with experience that “money can’t buy.”

He highlighted his sense of humor recently with a super­hero-themed “Avenger: MoCo” television ad, running through his qualifications (including that he was the force behind Montgomery Cares, the county’s system of health care for uninsured low-­income adults), while also shooting lasers out of his eyes and performing what could be the highest karate kick out of all six Democrats in the June 26 primary.

“I’m a political insider. That’s precisely what you want,” Leventhal, 55, said in an interview. “The political structures are very complex. And if you don’t bring a very sophisticated understanding about how to marshal political forces for progress, you’re not going to get anything done.”

Leventhal has played a key role in council efforts to strengthen social services in Montgomery, including effectively eliminating homelessness among the county’s veteran population and establishing Montgomery Cares, which Leventhal calls his proudest achievement.

He was first elected to the council in 2002, running on then-County Executive Doug Duncan’s “End Gridlock” team, which largely focused on support for building the Intercounty Connector.

He also was a founder of Purple Line Now, which favored building the light-rail line between Montgomery and Prince George’s counties.

Leventhal says he would be an “experienced inside player” attractive to the county’s business community. At a forum by the pro-business group Empower Montgomery in April, he said his first budget as county executive would include a “significant reduction” of the county’s energy tax. Leventhal, who lives in Takoma Park and recently earned a doctorate in public policy from the University of Maryland, has also said government wages are growing too fast.

“Compensation should be fair, but compensation at every level has exceeded increases in private-sector compensation year to year,” he said. “We pay too much at the high end. If I’m executive, I’m going to have hard conversations with department heads.”

He said he would work with religious groups to discuss siting affordable housing developments on their properties. He also pointed out that he is the only candidate who speaks Spanish fluently, in a county where nearly one-fifth of residents identify as Hispanic or Latino.

But Leventhal has developed a reputation within the county’s political community as too hard-charging at times, in part because of incidents at televised council meetings, such as one in 2014 in which he upbraided a department head over issues with the county’s computer system.

“His heart’s in the right place, I think,” said Duncan, the former executive and a fellow Democrat. “As to how he would manage and lead an 8,000-person government, I don’t know. He sometimes gets too passionate.”

Leventhal says other council members are also what he describes as “testy” at times — but were lucky enough to keep it off camera.

“If the question is, ‘Have you ever lost your temper in your life?’ I would have to admit, yes, it’s happened,” he said. “One of those times was captured on video. Everyone I know has lost their temper at least once.”

Leventhal is one of three Democratic county executive candidates using Montgomery’s new public financing system, which limits donations to $150 from individuals who live in the county. He had qualified for $465,504 in matching funds and requested an additional $23,926 as of mid-June, behind council member Marc Elrich (D-At Large) but ahead of former Rockville mayor Rose Krasnow.

Leventhal has racked up a slate of endorsements from diverse communities, including the Latino Democratic Club of Montgomery County, the Caribbean-American Political Action Committee and former NAACP head and Maryland congressman Kweisi Mfume, who lauded Leventhal for being a “staunch advocate for those who need help the most.”

“I think I bring the broadest geographic base of any candidate for executive,” Leventhal said.

Read the earlier profiles: