If you want a conventional analysis of the possible vice presidential picks for presumptive Democratic presidential nominee Sen. John Kerry, you can’t do much better than John J. Miller on National Review Online.

Miller, however, overlooks important factors — the most important factors — in picking a running mate.

These factors follow a theme, well-known to all presidential aspirants, but apparently less well-understood among media commentators, who consistently guess wrong about veep picks. The theme: The vice-presidential nominee must make the presidential nominee look good by comparison. The v.p. cannot in any way show up any shortcomings in the would-be Prez.

In Kerry’s case, that presents a real pickle, a dilemma not seen since the 1988 campaign of George H. W. Bush, a man perceived at the time, like Kerry now (though the media will not admit it), as relentlessly second-rate.

First, the v.p. nominee has to be almost as tall as John Kerry, but not quite as tall. Neither can he be appreciably shorter (think Mutt ‘n’ Jeff). Note to Kerry campaign: Check heights. The Senator stands six feet four. Somewhere between five-ten and six-two would be ideal. In addition, the nominee cannot be fat, or even appear to be fat when standing next to the long, lanky Yankee. In the event Kerry picks a woman, she cannot be Donna Shalala or Madeleine Albright.

Second, the veep cannot be a better speaker or debater than John Kerry. That presents some problems, since John Kerry is one of the duller characters on the national stage, speech-wise, being devoted to the sound-byte drone style of address and debate. Al Gore would be perfect in this regard, a born second banana, a devotee of the talking point, and obviously not quite gifted. Al Gore has a problem or two, however. (Campaign note: Consider Boston Mayor Thomas Menino, dubbed “Mumbles” by talk show host Howie Carr.)

Third, the candidate cannot possess any kind of independent star power greater than the presumptive wattage of Senator Kerry. Forget Hillary, in other words. And a long list of others, let us count the ways of political starshine: Chuck Schumer, Jon Corzine, Jim McGreevey, Ed Rendell, Skip Humphrey…Ah, the snores in the offing, as we contemplate middling tall, cautious speaking politicians of no particular radiance.

Fourth, a political reality. John Kerry, already the member of a loser class for nearly half a century in the Presidential stakes (Congress), cannot pick another member of Congress or former member of Congress. That limits his choices to modestly tall, fairly dull governors, big city mayors, or former cabinet members in Democratic administrations, who have achieved no Q-factor eminence, or at least not too much.

Fifth, the candidate cannot be radioactive in any way. Think of the Tom Eagleton imbroglio early in the McGovern campaign. Eagleton, as you may not remember, turned out to have been committed to an asylum at one point, where he received electroshock therapy. What is today’s version of radioactive? Kerry cannot afford any direct connection to the gay rights lobby, not with gay marriage on the national stage. Okay, so we’ve got six feet (maybe a little more), modest speaking ability, minimal star power, no Senators or Reps, no fame, and now we’ve got no controversy, either.

Sixth, Kerry cannot afford another “military” man or (heavens!) woman. Kerry was a Lieutenant (J.G.). Virtually any military achiever will outrank him. Neither can Kerry afford another anti-Vietnam activist.

Finally, although Kerry won’t want to pick somebody of whom the first reaction is, “Who?” he almost certainly will. He might choose a judge, though it’s hard to find a judge who cannot talk better than Kerry, at least a little. It’s a fair indicator of Kerry’s dilemma that the two candidates who strike me as nearly ideal are Christine Todd Whitman and the pre-Presidential George W. Bush.

No, I’m afraid we’re in for the Democratic equivalent of Dan Quayle.