Senior Regional Correspondent

Prince George’s County’s reform-minded leader Rushern L. Baker III tasted sweet vindication in Tuesday’s special election when the candidate he backed scored a landslide victory in the Democratic primary for an open County Council seat.

In practical terms, the triumph by Derrick Leon Davis meant that Baker (D), who’s been county executive for nine months, will have an important new ally on the council. It illustrates that Baker’s political organization, which aided Davis’s campaign, continues to get stronger.

In addition, Baker had personal reasons to delight in the achievement. Davis won in the electoral district previously represented by Leslie Johnson, disgraced politician and spouse of the equally disgraced former county executive Jack B. Johnson (D) — who was Baker’s political archenemy for the past decade.

Both Johnsons have pleaded guilty to felonies in a federal corruption investigation and are almost certainly headed to prison. Meanwhile, Davis’s victory on the Johnsons’ home turf will help Baker as he tries to extend a string of successes he’s enjoyed in recent months in battling the county’s ethics troubles, economic woes and poorly managed government.

It’s too early to say that Baker has turned around the county government after Johnson’s shaky, eight-year administration. But he’s off to a solid start, and the special-election victory confirms that voters approve.

Davis, a former school system official, and his backers praised Baker’s vision for the county at the victory party at the Fraternal Order of Police lodge in Upper Marlboro on Tuesday evening.

“The result is a decisive endorsement of the county executive’s agenda. It’s a new day in Prince George’s,” said Bernard Holloway, a senior adviser to the Davis campaign.

(Davis still has to defeat the Republican nominee, Day Gardner, in the general election Oct. 18, but that is a minor formality in the overwhelmingly Democratic District 6. Consider: Davis received 3,570 votes in the Democratic primary. Gardner received 97 in the GOP primary.)

Baker’s efforts to clean up county government have drawn praise from local business and civic leaders. It’s pretty simple: They said officials appointed by Baker seem to be honest. Baker also successfully promoted state legislation that makes it harder for politicians and developers to engage in the county’s notorious “pay to play” culture.

“We’re certainly not seeing and hearing any of that going on. As far as I know, there isn’t any semblance of that that’s left,” said Jim Estepp, president and chief executive of the Greater Prince George’s Business Roundtable.

There’s reason to be wary. Skeptics said the real estate market is so slow that there’s little reason to offer bribes these days anyway. Also, Estepp noted that it takes a while to “root out all vestiges of people who had association with the past administration that perhaps may not be suited for government.”

On the economic front, Baker had two modest victories this week. On Monday, Maryland announced that it will move the state housing department headquarters from Anne Arundel County to New Carrollton. On Wednesday, a council committee approved Baker’s signature initiative to create a $50 million incentive fund to help lure more private development to Prince George’s.

In July, Baker reached an initial agreement with the University of Maryland Medical System and other partners to build a long-awaited new hospital in the county. That would create jobs as well as reduce the need for Prince Georgians to travel elsewhere for health care.

The Johnson administration was never able to move ahead on the project, partly because the state government and other parties didn’t entirely trust it.

Finally, the Baker administration is said to have raised the overall quality of management and transparency in many county departments. This has been a major chore because some departments — such as housing, environmental resources and health — were so badly run.

Amina Anderson, senior program officer at the Community Foundation for Prince George’s County, said philanthropic leaders have been impressed that the Baker administration has consulted with them and streamlined procedures for obtaining grants.

“He and members of his staff really spent a lot of time listening to folks in the county in the nonprofit sector about what their concerns were, what their needs were, how the county should be responding,” she said. The new grant process “is modeled on some of the best practices” in the field, she said.

Baker lost to Jack Johnson the first two times that Baker ran for county executive. Now Baker’s making strides overcoming Johnson’s troubled legacy, while Johnson prepares for years in prison. Baker’s not the type to gloat, but even Mother Teresa would find that turnabout gratifying.

I discuss local issues at 8:51 a.m. Friday on WAMU (88.5 FM).