A Nov. 25 Metro article misspelled the name of Kevin O'Keeffe, a Democratic candidate for Congress in Maryland's 3rd District. (Published 11/29/2005)

After he lost his congressional primary race in 2002, Oz Bengur thought his best chance to make it to the House of Representatives was gone.

The 2nd Congressional District seat he was seeking had been vacated by Republican Robert L. Ehrlich Jr., who was running for governor. Bengur, a Democrat, knew the realities of congressional politics in Maryland: It is virtually impossible to oust an incumbent, and open seats that challengers, especially novices such as him, actually have a shot of winning come around only rarely.

So the Towson financial consultant gave up his dream of Congress and started thinking of state office instead. But this year, another opportunity surfaced. U.S. Rep. Benjamin L. Cardin (D) announced he was vacating the 3rd Congressional District seat to run for the Senate seat of Paul S. Sarbanes (D), who is retiring.

"I didn't anticipate there would be [an open seat] for a number of years," said Bengur, who has also lived in the 3rd District. "My guess is, having two open seats in Maryland within three years is probably unusual."

In fact, there have been just 10 such vacancies in the 104 congressional elections held in Maryland since 1980.

As Maryland heads into an election year with a heated gubernatorial race and an open Senate seat, the 3rd District race is the only one of Maryland's eight House contests that promises real competitive drama. All other incumbents are expected to run for reelection. If the past is any guide, they will overwhelm their opponents with their name recognition and ability to raise money.

The 3rd Congressional District wends amoeba-like through parts of Anne Arundel, Howard and Baltimore counties and Baltimore. It includes traditionally liberal areas, such as Annapolis and Columbia, and more conservative ones, including Parkville and Crofton.

The seat has a special allure to aspirants because of its history as a gateway to higher office. Sarbanes represented the district before moving on to the Senate in 1977. Barbara A. Mikulski (D) replaced him and served until 1987, when she, too, went to the Senate. Cardin moved from the Maryland House of Delegates to fill the congressional opening.

Incumbents in Maryland are so entrenched that in the past 25 years they have lost only three of 94 general elections, a Washington Post analysis has found. That's a reelection rate of about 97 percent, about two percentage points higher than the national average for that period. Just one incumbent was knocked off in a primary during that time.

In 2002, when Chris Van Hollen (D) ousted Rep. Constance A. Morella, a Republican, from her seat in the House, it was in a district redrawn to favor a Democrat. It was also the first time a Maryland congressional incumbent had been unseated in a general election since 1990, when Rep. Wayne T. Gilchrest (R) defeated Democrat Roy P. Dyson, considered highly vulnerable after the suicide of a longtime aide and allegations of campaign finance improprieties.

Like challengers elsewhere, those in Maryland have been thwarted by the fact that once the winners lay claim to the sought-after seats, they tend to hold on. Over the last 50 years, the 3rd and 7th districts have had only four representatives each; the 4th and 5th districts have had five each. U.S. Rep. Steny H. Hoyer (D), the longest-serving member in Maryland's House delegation, has represented the 5th District since 1980.

So when a seat opens up, candidates pounce.

In the 3rd District Democratic primary, Bengur is joined by Peter L. Beilenson, a former Baltimore health commissioner; state Sen. Paula Hollinger; and Kevin O'Keefe, a former aide to Anne Arundel County Executive Janet S. Owens, who is thinking of jumping in herself. John Sarbanes, a lawyer and the son of the retiring senior senator, is also running.

Congress had always been "in the back of my mind," John Sarbanes said. "Ben has represented it very well for a very long time, so once the chattering began as to whether he was pursuing the Senate seat . . . it seemed like a natural thing to get into."

Hollinger said she considered running for Cardin's seat "about seven years ago," when Cardin was thinking of running for governor. "I spent the summer putting together a congressional campaign," she said.

But when Cardin decided against a gubernatorial bid, she stood down.

If Cardin had decided to run for reelection this time, Hollinger said, she would "absolutely not" have run.

"Politics is about opportunity and being at the right place and the right time," she said.

At first, Bengur thought he might run for the 2nd District seat again when Rep. C.A. Dutch Ruppersburger, who beat him in the 2002 Democratic primary, was mulling a run for the Senate. But when Ruppersburger decided to stay put, Bengur knew his only option was the 3rd.

"I would not have challenged an incumbent, and certainly not Ben Cardin," he said.