Las Vegas ? An incumbent is running in Nevada’s 1st Congressional District, yet the race resembles one for an open seat. Why? Because it is in this city, which could startle the nation come November.

Republicans control the House of Representatives 222-211. There are two independents. The challenger here, City Councilwoman Lynette Boggs McDonald, 38, attracts interest because she participated as Miss Oregon in the 1989 Miss America pageant, and if elected she will be the first African-American woman Republican ever to serve in the House. But most important, this race is one of the small number in 2002 probably fewer than 40 that are truly competitive. Few of those involve incumbents. This is one of the races that will determine who controls the House, and it will turn on small local factors.

The incumbent, seeking a third term, is Shelley Berkley, 51. Although the district as configured in 1998 had an even more substantial preponderance of registered Democrats than it now has, she won with just 49 percent of the vote while outspending her rival more than 2-to-1. In 2000, she won 52-44, again with a substantial spending advantage.

She is a generally centrist Democrat, although very attentive to organized labor. She is an energetic campaigner and prolific fund-raiser in a city that is a magnet for contribution-hungry politicians nationwide. Fund raising and other advantages make incumbents difficult to dislodge, especially immediately after redistricting. In democracy, as quaintly understood, voters pick their representatives. American democracy increasingly reverses that. Legislative districts are drawn to protect incumbents who, effectively, pick their voters.

But Berkley has not been helped by the redistricting made necessary by the fact that this is the nation’s fastest-growing major city a city that prints a new phone book twice a year, and that needs 12 new schools a year to accommodate 6,000 new residents a month. The portion of northwest Las Vegas that has been put into the redrawn 1st District had 50,000 residents four years ago. Today it has 150,000. Berkley is hardly an incumbent there.

Nevada’s senior senator, Harry Reid, now in his third term, looms large in Washington he is Senate majority whip. But he was re-elected in 1992 with just 51 percent of the vote and in 1998 with 48 percent by only 428 votes. Why? Because everyone starts almost from scratch in every election. Even incumbents quickly become strangers to the constantly churned electorate in a state whose population increased two-thirds in the last decade.

This city’s current preoccupation is President Bush’s decision, capping decades of study, to store nuclear waste in Yucca Mountain 90 miles northwest of here. Every Nevada politician opposes this but Bush remains popular.

The abiding preoccupation of this city that depends on visitors arriving at McCarran Airport this city that lost 20,000 jobs immediately after Sept. 11 is attracting businesses to diversify the economy. This and charter schools, which help explain McDonald’s support among African-American civic leaders who normally support Democrats, are her strongest passions. Poised (a beauty pageant can be spring training for politics), articulate (she has worked as a journalist) and entrepreneurial by conviction (Can you have too many Reagan election posters? Her office is trying), she is a born booster.

In this city of perpetual unpacking, voter turnout spikes in presidential election years, but sags, particularly among Democrats, when, as this year, there is not even a gubernatorial or Senate race. And in 2000 Berkley ran two points behind Gore’s performance in her district.

In 32 of the 34 mid-term elections since the Civil War, the party holding the presidency has lost House seats. However, Democrats have gained seats in the three elections since 1994, and only three times in the 69 elections since the Civil War has a party gained seats in four consecutive elections.

Which pattern will prevail this year depends partly on the fate of a conservative, pro-life African-American Republican woman. That is implausible, but not more so than this city exploding across the desert.

George Will is a columnist Washington Post Writers Group.