THIS IS an election year in Maryland, and the slates of candidates for local offices are crowded in many places. A rare exception in the Washington suburbs is for the top job in Prince George’s County, where County Executive Rushern L. Baker III, a Democrat, faces no challenger in his party’s primary in June nor any Republican opponent in the general election in November. Notwithstanding a couple of quixotic independent candidacies, Mr. Baker is coasting to reelection.

His cakewalk is a testament to his achievements in office and to the sea change he has effected in Prince George’s, one of the nation’s largest and most affluent majority minority localities. Just 3½ years ago, the county, forever bristling at suggestions that it played the role of poor relation to its suburban neighbors, was mired in a memorably tawdry scandal.

A sticky-fingered county executive, Jack B. Johnson (D), had been caught shaking down a businessman, and his wife Leslie had tried to spirit nearly $80,000 in cash from their house in her bra, only to be caught in the act by FBI agents. Both went to prison not long after Mr. Johnson left office. As laughable as it was appalling, the episode reinforced the county’s image as a place where graft was a barrier to new business.

Mr. Baker took office in December 2010 promising a new day in the county of 900,000 people, and he has largely delivered on that promise. Given the corruption of the Johnson era, it might have been enough for him to preside over a scandal-free administration. In fact, he has done much more.

Mr. Baker has pushed for ethics reforms (though he has stopped short of creating an office of inspector general, as he originally proposed). He has infused Prince George’s with a sense of economic dynamism and renewed upward mobility: proposing and closing a deal to lure a $1 billion resort and casino to National Harbor, moving to replace the county’s terminally impoverished regional hospital with a modern medical complex and jockeying to win the competition with Fairfax County to land the FBI’s new headquarters and the thousands of jobs that would follow.

In line with national trends and beefed-up local policing, crime of almost all sorts has dropped precipitously in the county since Mr. Baker took office. The homicide rate last year was less than a third what it was in 2005. With the exception of Whole Foods, which is making its first foray into Prince George’s, few things can rebrand a place faster than radically safer streets and neighborhoods.

As Mr. Baker acknowledges, plenty remains to be done. The schools are still not up to the expectations of many demanding parents in a generally well-educated county. While Mr. Baker won the right to name a new schools superintendent, he failed to convince lawmakers in Annapolis that he should assume complete control of public education in the county. Still, Prince George’s has a leader it can be proud of and one that its residents deserve.