Derrick Davis talks with senior citizen after they voted at Evangel Cathedral. (Mark Gail/THE WASHINGTON POST)

Derrick Leon Davis, a Democrat, coasted to an easy victory Tuesday in the race to fill the Prince George’s County Council seat vacated by Leslie Johnson.

With all 26 precincts reporting, Davis had 4,004 votes to Day Gardner’s 389.

Davis, a former county school system official, is chairman of the Maryland Automobile Insurance Fund, and he tried twice before to win the seat. He faced Gardner, a businesswoman, who ran unopposed in the Republican primary.

Davis, 43, who worked with high-poverty schools as an administrator, said improving the schools and taking care of the county’s senior citizens are among his chief goals.

“I want to make sure that we uplift our school system and hold high the economic achievement of every child,” he said. “That is how we attract businesses. Once they see that type of effort, they would be remiss in not coming and participating in the climate we are creating here in Prince George’s County.”

Turnout was light in the overwhelmingly Democratic mid-county District 6, which stretches from struggling inside-the-Beltway communities to gated neighborhoods with mega-mansions. By midafternoon, only about 2,500 voters had cast ballots in the district, which has more than 77,000 registered voters.

Davis easily won the 14-way Democratic primary in September after receiving support from County Executive Rushern L. Baker III (D).

The campaign between Davis and Gardner was low-key, without one-on-one debates. The candidates engaged mostly in direct-mail campaigning and neighborhood canvassing.

“A lot of people out there are not happy with business as usual,” said Gardner, 56, before Tuesday’s vote. But she acknowledged the odds against her. “It is an uphill battle. I know I am the underdog in this race.”

The district, like the rest of Prince George’s, is overwhelmingly Democratic, with 65,780 registered Democrats out of 77,152 registered voters.

In the primary, Davis received 3,570 votes, or 55 percent of the Democratic ballots cast. Gardner received 109 votes in the Republican primary, 100 percent of those cast.

Davis will replace Johnson, who was arrested in November after federal investigators monitoring a wiretap heard her husband, then-County Executive Jack B. Johnson, instruct her to flush a $100,000 check down the toilet and to stuff $79,600 in cash into her underwear.

Johnson initially refused to vacate her position. But after a public outcry and calls from fellow council members to step down, she resigned in July. She and her husband, who pleaded guilty to bribery and tampering with evidence, are awaiting sentencing.

Davis came in second to Johnson in the Democratic primary in September 2010.