President Anthony Principi? President Ann Veneman? President Mel Martinez? Household names? No. Possible presidents? Yes.

Over the years, members of the Cabinet have been added to the Presidential Succession Act in the order in which their departments were created. In all the hubbub of creating the Homeland Security Department, however, someone forgot to add the newest member to the act.

But that might not be such a bad thing. Instead of randomly shoehorning the secretary of Homeland Security somewhere into the potential presidential lineup, the time has come to go back to square one and rethink what presidential succession is all about. We all hope such an exercise will prove to be merely academic, but in a time of war and terrorism, making sure we are prepared is no trivial pursuit.

When Congress impeached President Andrew Johnson, there was no vice president. Next in line for the presidency, had Johnson been removed from office, was the President Pro Tem — the very person leading the impeachment against Johnson in the Senate.

Since 1947, the list of presidential successors has started with the vice president; next come Congressional leaders, and then Cabinet members. But current law doesn’t really make much sense. While the Speaker makes the list, the Senate Majority Leader does not. If the secretary of Transportation is in line to take over as president of the United States, surely you would think the Senate Majority Leader would make the cut.

Sen. Mike DeWine (R-Ohio) and Rep. Tom Davis (R-Va.) propose that Homeland Security Secretary Tom Ridge be put eighth in line, jumping over two-thirds of Ridge’s Cabinet colleagues. It sounds sensible to pass the baton through the ranks with Homeland Security coming before, say, Labor or Education. But that’s because Sept. 11, 2001, weighs so heavily on our national consciousness. Remember, though, that presidential succession may be required for health, scandal or other reasons as easily as for terrorist reasons — so bunching the “security” Cabinet positions at the top of the list may not be the best idea. It also begs the question of why Cabinet members belong in the line of succession at all: After all, who elected them to anything?

There are any number of other ways to think about presidential succession. Some experts suggest that, after the vice president, the line of succession go immediately to the nation’s governors, starting with biggest states first. Governors are executives (unlike Congressional leaders) and have been elected by at least some of the nation’s voters (unlike Cabinet members). But how does that square with the Constitution’s bedrock principle of federalism?

The framers of the Constitution thought the person with the best claim to be next in line was the runner-up in the presidential election. In fact, the founders gave the next highest vote getter the vice presidency, but that idea went out in the 1800s.

On what basis, then, should we determine presidential succession? The way to approach this is to answer the fundamental question first: What is it we want to ensure during presidential succession? The answer has to be continuity and competence — continuity in leading our government by an official who is competent to do so.

The presidency is a unique job, and the best place to look for those who are up to the job is among those who have already done it: the ex-presidents. Former presidents (excepting those who are otherwise disqualified from holding the office) form a pool of successors with special advantages: They know the duties of the office; they already have Secret Service protection; they are dispersed around the country and less susceptible to a terrorist attack that incapacitates leaders in D.C.; and they might even be able to take some of the “politics” out of a time of crisis by acting as a “caretaker” president until the next election, where they are less likely to run.

In the end, almost any answer to the question of presidential succession could be considered arbitrary. But in a time of crisis, you want an experienced pilot who’s ready to take over — not someone who’s flying solo for the first time.

John Schall has served as an aide to former Senate Majority Leader Bob Dole (R-Kan.) and former President George Bush. He heads the National Business Coalition on E-Commerce and Privacy.