IT’S NO mystery why some residents of Prince George’s County are enamored of term limits for local elected officials. Adopted by voters in 1992 and reaffirmed at the ballot box in 2000, the limits allow elected officials a maximum of two consecutive terms in office, or eight years, before showing them the door.

The term limits ensured the departure, in 2010, of a sticky-fingered county executive, Jack B. Johnson, who now is serving time in federal prison for corruption. For years, the limits have rid the County Council of a rogue’s gallery of charlatans, buffoons and, most common, swindlers who helped themselves to public funds. Good riddance.

So why not ensure that the rascals are thrown out on a regular schedule, without the headache of a campaign and election?

The current crop of county officials say the answer is competitiveness. They decided to ask voters at referendum this November to extend term limits to three terms (12 years). As the only locality in the Washington area with term limits, they believe Prince George’s is at a disadvantage in contending with its neighbors.

That proposition is hard to prove or disprove, but it’s logical enough. It’s certainly true that in the aggregate, the Prince George’s County Council has less experience than its counterparts in Fairfax and Montgomery counties, which include a number of members who have served 16 or more years. (Sharon Bulova, the well-regarded chairman of Fairfax County’s Board of Supervisors, has served on that body since 1988 and chaired it since 2009.) And with members coming and going so often, it may be more difficult for the council to develop the continuity required to carry out long-term strategies effectively.

As Andrea Harrison (Springdale), a member of Prince George’s current, all-Democratic council told The Post: “We are always starting over.”

Fair point. The truth is that with a population of more than 900,000, the county is no longer mainly a sleepy amalgam of scruffy farms and bedroom suburbs. And, for the moment at least, the caliber of County Council members is markedly better than it has been in the recent past.

Voter apathy also seems to be eroding. In a county where incumbency has all but guaranteed reelection to a second term, voters shocked the political establishment last month by evicting the scandal-plagued clerk of the county court, Marilynn Bland.

That was a promising sign. If voters are paying attention, as they increasingly seem to be in Prince George’s, then term limits are beside the point. Think a council member or county executive is sleazy or ineffective? The ballot box is an effective means of eviction. Council members, mindful that voters have voted for tight term limits twice before, were wary of scrapping them all together. Hence the cautious proposal to extend the limit to three terms. Fair enough.