Washington ? Whom would you choose to replace you? Whom do you trust enough to be your existential understudy? It is a question most humans never face directly. But presidential nominees do, and it is among the most telling decisions they ever make. It is a choice they actually live with every day of the campaign and then during their presidency if they win.

Howard Dean’s collapsing crusade and John Kerry’s ascendancy give a new shape to the quadrennial quest for a running mate and other heavy hitters to staff an administration that is still notional. It is the political junkie’s equivalent of Fantasy Football — except there are real-life consequences to the notice from the media or the candidate in this new phase of Campaign ’04.

Too early to raise the topic? Don’t underestimate the force of “jobs for the boys” as a factor in big political campaigns. Years divisible by four provide the opportunity for epoch-defining debates and personal grace, or disgrace, under pressure. But they are also giant job hunts. Auditions were begun long ago.

On the campaign trail, a candidate gets to test and observe the judgment and skills of people he hardly knows. That has certainly been the case for Dean, who attracted a glittering cast of former Clinton-Gore foreign policy advisers who are now perhaps re-examining their employment prospects for the next four years.

Both in his years in the Senate and his months on the campaign trail, Kerry has tended to do foreign policy on his own. Unlike Dean or George W. Bush four years ago, Kerry does not project a need to have lots of “safe hands” around him to deal with complicated subjects, such as whether the world is safer with Saddam Hussein in jail than not. (It’s stranger than you think: Dean’s foreign policy advisers reportedly argued against putting out that campaign-curdling statement. Dean’s political advisers had urged it to solidify the “base.”)

The difference also surfaces on the choice of a Democratic running mate. Paradoxically, Kerry would be less dependent on the Washington establishment than Dean might be.

It is difficult to imagine Dean looking outside Washington for a Democratic governor or mayor to provide regional, practical and/or gender balance, as Kerry can. The former Vermont governor would be compelled to look instead for a reassuring figure with deep congressional experience.

Kerry can redefine balance in a bitter and close contest for a small number of decisive swing votes if 2004 resembles 2000. For example, Bill Richardson of New Mexico could help Kerry in the expected dog-eat-dog fight for Latino support.

Or Kerry can give a new twist to regional balance: Instead of going to John Edwards to try to dent Bush’s hold on the South, he could try to pick off a decisive Midwestern state feeling economic distress. Indiana fits that description, and Sen. Evan Bayh is a proven vote-getter there.

On foreign policy, a President Dean would be under pressure to name and immediately empower an internationally known figure as secretary of state, if only to calm the inevitable doubts about Dean’s inexperience on the world stage. A President Kerry would be more likely to do much of the diplomacy himself, rather than name and rely on an Al Gore as his chief diplomat, as some have speculated Dean might. (In that case, why not Bill Clinton?)

Democrats are not alone in facing this guessing game. Vice President Cheney’s health seems fine now, but past heart problems raise a question mark for a rough campaign. Republicans in the Senate assume that Tennesee’s Bill Frist would join the ticket if Cheney doesn’t run. Homeland Security Secretary Tom Ridge has also been mentioned.

A re-elected Bush will need a new secretary of state. Colin Powell has told a wide circle of friends that he will not be back. (Good news for Bush, bad news for eager publishers: Powell is also saying that he will not write a memoir about his time in office, just as Gen. George Marshall, Powell’s hero, did not.)

Condoleezza Rice or Sen. Richard Lugar would hit the ground running as Powell’s replacement. Lugar’s speech at the Munich Conference on Security Policy last weekend provided the most detailed, lucid description of Bush’s Greater Middle East Initiative I have heard. Don Rumsfeld’s speech at that same event emphasized his accomplishments as defense secretary and thus had a valedictorian quality — faint, admittedly, but more than enough to plant hope in the hearts of this capital’s aspiring officeholders in this campaign season.

Jim Hoagland is a columnist for Washington Post Writers Group.