Howard Wolfson, former communications director for Hillary Clinton, has been writing for us from Denver. Here are his thoughts on McCain's upcoming v.p. selection.

What will John McCain's pick, due tomorrow, of his vice-presidential running mate, say about him to the American people?

McCain is running ahead of the generic Republican ballot because many Americans believe he is an independent maverick, an image he forged during his 2000 run. If McCain picks a pro-choice running mate like Tom Ridge, or a woman like Meg Whitman, or a Democrat like Joe Lieberman, he will do much to help cement that image, which has justifiably been tarnished during the Bush presidency. Such a pick would shake up the race and jumble the electoral math.  It would send a strong signal to independents and moderates that McCain would conduct his presidency in a different way than George Bush has. Perhaps for that reason I'm told that the Bush White House is counseling against such a pick.

A real maverick might make such a pick.

The betting here is that McCain won't. Why?

Over the last eight years McCain has moved considerably to the right and disowned many of the moderate positions that he once held dear. This was done in a clear attempt to assuage the right wing of his party and secure the presidential nomination.

Despite this, the right of the Republican Party remains suspicious of him. The lack of enthusiasm for him among base Republicans is palpable. For that reason he is likely not in a position to make a bold pick--a pick that he may well be more comfortable with in his heart.

A Romney, Pawlenty, or Huckabee pick would send a clear signal to America: McCain--Maverick no more.