On Election Day, angry voters in Maryland's suburban heartland toppled county executives, wiped out county councils and unseated sheriffs and courthouse clerks, some with more than 20 years' tenure.

In a fit of anti-incumbentism, the predominantly white and wealthy Montgomery, Howard, Anne Arundel and Baltimore counties elected unknown Republicans and dissident Democrats.

Why?

Although these four suburban counties are politically estranged in the General Assembly, they share some key problems and characteristics.

First, they're too crowded. Rapid growth and the government's failure to provide adequate public facilities have produced vast anti-growth sentiment. Gridlock, impact fees on new development and portable classrooms have become common.

Second, taxes are too high. As crowding and inconvenience have increased, so has the cost of government. Quality of life is down, property taxes are up. Suburbia is where the 1980s boom in home prices and tax assessments took place. When assessment appeals tripled this spring, suburban officials should have expected that angry voters would descend on them this fall.

Third, these suburban voters are independent. Party loyalty hasn't stopped them from looking beyond the Democrats for solutions.

For decades, Democratic incumbents in the suburban counties were comfortable with the fact that suburban taxpayers finance the rest of Maryland's needs and get little back in return. Suburban Democrats played along with the annual stick-it-to-the-suburbs game in Annapolis, because they always had enough tax money to make up the difference. In addition, those who went along with the game often were rewarded with political promotions by the Annapolis power structure.

But suddenly in the late 1980s, the suburbs ran out of money. Local incumbents found themselves forced to choose between roads, schools, teachers' salaries and a property taxpayers' revolt, a no-win situation.

On Election Day, the Democratic domination of Maryland's suburbs collapsed. Voters looked closely at tax-trim referendums and decided that instead of shooting themselves in the foot by cutting services, they would shoot the incumbents between the eyes.

Technically, they were shooting the wrong incumbents. They blamed the closest level of government -- the council and executive -- for the state's funding shortfalls.

On the other hand, suburban incumbents who were double-talking their constituents richly deserved to be voted out of office.

When homeowners complained to them about skyrocketing tax assessments, local incumbents palmed it off as a state matter. When tax protesters proposed tax-trim referendums, the incumbents condemned them without offering alternatives. And while commuters fumed in traffic and children crowded into portable classrooms, the incumbents claimed that the counties were getting their fair share from Annapolis. Even as they leave office they blame their defeats on too little self-promotion. To the bitter end, they remain out of touch.

When grievances boil over in a democracy, voters react. That's not revolutionary; it's normal. Suburban voters want their needs met without being taxed out of their homes. That's not selfish; it's reasonable.

Maryland's political power is shifting to the suburbs. The four counties that overthrew their incumbents are the state's fastest growing areas and contributed 51 percent of the votes cast for governor this year.

Presumably the new leaders swept into office on Election Day will remember how they won and remind our Annapolis officials that, henceforth, politicians -- at any level -- who play stick-it-to-the-suburbs will be held accountable.

The writer is vice president of a Silver Spring development firm and a frequent contributor to this page.