Scott K. York in a 2006 Loudoun Board of Supervisors meeting. (TRACY A WOODWARD/The Washington Post)

FOR MUCH of the two decades that Scott K. York has served on Loudoun County’s Board of Supervisors, the county has been among the nation’s fastest-growing localities, and its richest as measured by median income. Having added more than 50,000 people since 2010, Loudoun’s population is now approaching 370,000, more than double the number who lived there when Mr. York was first elected in 1995.

As the board’s chairman since 2000, Mr. York has presided over this explosive growth and the accompanying political tumult — over public schools, land-use planning and transportation, to name a few areas of contention. Yet through seesaw shifts in party domination of local politics, and fierce debates over the pace of development, Mr. York has been a steadying, serious-minded influence. The fact that Loudoun has withstood such dizzying change and remains prosperous and well managed is testament to his calming, level-headed leadership.

Mr. York was prepared to retire after this year, at the completion of his current term; he even announced his support for a board colleague to succeed him. But following revelations of domestic abuse, that colleague, Republican Shawn M. Williams, withdrew from politics. And as it became clear that Mr. Williams could not be a viable candidate, Mr. York changed his mind and announced he would run again. Although he considers himself a Republican, Mr. York will appear on the ballot as an independent.

He deserves reelection both on the strength of his record and the shortcomings of the other candidates’ relevant experience. His opponents include a Democrat, Phyllis J. Randall, a mental-health therapist; and a Republican, Charles King, a lawyer. Neither Randall nor King has held elective office.

While Ms. Randall, who has served on some state boards, has advanced constructive ideas about tightening ethics rules, she has also ranted against what she called a “full scale invasion” of illegal immigrants, which suggests she may not have the temperament to lead a county of Loudoun’s size and complexity.

As for Mr. King, his solid record of community involvement is undercut by his agreement to provide legal representation for Eugene A. Delgaudio, a member of the Board of Supervisors who was accused of corruption. We don’t generally look askance at lawyers based on the clients who hire them, but in the case of Mr. Delgaudio, a Republican who is among the most divisive figures in the county, Mr. King was ill-advised to run for the county’s top elected position immediately after having mounted a spirited defense for so incendiary a figure.

Mr. York, to his credit, has stood above the board’s occasional shenanigans and the provocations of its more colorful characters. He generally sticks to a dry, just-the-facts delivery that encourages rational debate. That trait will be in demand as the board prepares to grapple with how to accommodate demands for increased density and development around Loudoun’s two new Silver Line Metro stations, which are scheduled to go into operation by 2020. In previous fights over development, Mr. York has proven himself able to chart a centrist course.