Viewers of the popular TV show “The West Wing” recently got an insight into one of the most serious unsolved problems that could flow from a terrorist attack on Washington.

With the vice presidency vacant, the Republican speaker of the House, Glenallen Walken (John Goodman), became acting president when Democrat Josiah Bartlet (Martin Sheen) stepped aside temporarily after his daughter was kidnapped. He had to resign his House seat.

Aides to Bartlet worried Walken would use the situation to change administration policies. In the end, that didn’t happen, and the daughter was rescued, leaving Goodman neither president nor a House member.

Until Sept. 11, 2001, the possibility that both the presidency and the vice presidency would be vacant seemed far-fetched, especially after passage of the 25th Amendment to fill a vice presidential vacancy.

Two years later, few members of Congress have shown any urgency about dealing with that potential problem, as well as the question of filling vacancies if a large number of House members were killed or incapacitated.

“Two years is too long,” says Sen. John Cornyn, R-Texas, who has held hearings on the issues as chairman of the Senate subcommittee on the Constitution.

Of the two, Cornyn thinks the easier one to fix is to clarify who would assume the presidency if both the president and the vice president were killed.

Since 1947, the heir apparent has been the speaker of the House, a change made at the behest of Harry S. Truman. After he became president, he said an elected official, rather than the secretary of state, should be next in line.

Since Sept. 11, 2001, some experts have feared a more serious problem than elevating a speaker from a different party with a different agenda, like Republicans Newt Gingrich and Dennis Hastert during the Clinton administration.

A greater concern is that a devastating attack could decimate the House and let a small number of surviving members pick a new speaker who would be entitled to the presidency.

Cornyn said he hopes to introduce legislation to eliminate both the speaker of the House and the president pro tempore of the Senate from the line of succession to ensure the government remains under control of a member of the elected administration.

Its prospects are uncertain. Hastert, for one, hasn’t taken a position, a spokesman says, and in general seems disinclined to major changes.

There appears to be an even bigger obstacle to major changes in procedures for filling House vacancies if a large number of members were killed or incapacitated.

That requires special elections, which take some time. Two House Republicans, chairmen David Dreier of the Rules Committee and James Sensenbrenner of the Judiciary Committee, have proposed legislation to speed the process of electing replacements.

Others, including Cornyn and U.S. Rep. Martin Frost, D-Texas, would allow governors to fill House seats temporarily by appointment, pending a special election. That takes a constitutional amendment.

Given the fact that Congress has trouble passing 13 appropriations bills each year, the notion that lawmakers could act with dispatch on a far-reaching constitutional change seems optimistic.

Cornyn, displaying the optimism of a congressional newcomer, remains hopeful that action can be taken in both areas, starting with a bill in the current Congress to clarify presidential succession.

“It’s not just an issue for ‘The West Wing,”‘ he said. “The only question is whether there is the will to get it done.”

Carl Leubsdorf is Washington bureau chief of the Dallas Morning News.