I'll get us started...

Setting: Random Street, Swing State, USA.
Style: Man-on-the-street interview.

Cameraman asks person A, "Do you support how George W. Bush has run the country?"
Person A: "No."
Cameraman: "Who are you supporting for in the Presidential election?"
Person A: "McCain" or "I don't know".
Cameraman: "Can you name one position that John McCain differs from George W. Bush on?"
Person A: "Uh..."
(Montage time, with each person having a name tag on the bottom saying either "Does not support Bush, supports McCain" or "Does not support Bush, undecided.")
Person B: "Um..."
Person C: "Well..."
Person D: "I can't think of any..."
Person E: "Uhhhh...."
(As the screen darkens, similar hesitations are heard in the background as white text appears on the black background)
Text: "John McCain:
95% support for George W. Bush in 2007."
Text: "100% support for George W. Bush in 2008." (replaces the 95% line)
(wipe text)
Text: "If you can't think of the difference between George W. Bush and John McCain...
It's because there isn't any".
Close: "TCQuad PAC is responsible for the content of this advertising."

It's tight for a 30-second TV-style spot, but doable (I think...). You could follow that up with a similar line where people answer the question, but inaccurately (Iraq, health care, any other answer), with the accurate record. Anyways, that's what I'd do.

Fade up from black....Black and white pictures cross fade, a single male voice speaks:

"Before the Iraq war, the Republican architects for invasion told us many things.

This war would pay for itself.

This war would be over in months, if not weeks.

This was would bring stability to the Middle East.

This war would make us heroes in the middle east, we would be greeted with flowers and candy.

This war would help assure energy prices from spiking.

Now, the same Republican Architects are planning foreign policy for a new leader.

One who thinks staying in Iraq indefinitely is just like staying in post war Germany?

One who thinks singing about Bombing Iran is good foreign policy?

One who doesn't know the facts about which Iraqi faction Al Queda backs and which is aligned with Iran?

One who thinks the only solution is a military solution, when our army is stretched to the breaking point.

One who says he supports the troops but votes AGAINST the most important GI bill in 4 decades, then CLAIMS he supports it...."

Fade up to Wes Clark, as the voice that has been speaking

"The world is a dangerous place and we need clear judgment, not excuses and shifting rationale for wars that should never have been fought

We can't afford to waste our blood and treasure with another group of advisors who think like this, or a leader that agrees with them"

Obama/Clark for America `08

Fade up from black, image of a young family, standing in an emergency room, a mother holding a child, a father leaning over the desk, his head in his hands....

A lone female voice speaks....

There are millions of American families who live on the verge of losing everything they have worked their whole lives for.

One catastrophic accident, a breadwinner that can't work, a diagnoses for a treatment they can't afford can end the dreams of a lifetime and send that family into ruin.

We live in the greatest country in the world, built on the backbone of the American middle class worker.

But, something has gone wrong with that dream they were promised, we all were promised.  

In the richest country in the world, Millions live without health care, one small step from losing everything.

We have the best medical care in the world, but only if you can afford it.

Even those who can now afford watch the costs go up year after year, worrying
If soon they will also be one step from losing what they have, and if they will ever afford it again.

Is this how the American dream turns out?  

Is this the American dream we hand our children and our grandchildren?

Fade up to Senator Clinton standing against a dark background.

It's time we have a group of leaders that are for the American Dream again, for all Americans.  It's time to restore that American dream for generations to come.

Fade to banner

Paid for by Obama/Clinton '08 for America

Well, if I had a great big pile of money, why stop at one ad? I'd run a whole series. The series would be called "Ready to Lead?"
They will all be simple, with a minimum of text.

The first in the series is called "Iraq".
White type over black screen: "McCain on Iraq"
Then twenty-seven quickly cut seconds of McCain clips rambling about Iraq with the dates along the bottom of the screen. We will be greeted as liberators, this will be easy, major combat operations have ended, mission accomplished, nobody said this would be easy, The troops could stay in Iraq a hundred years, and fading to black on "it doesn't really matter when the troops come home."
White type over black screen. "Is this good judgment? John McCain, Ready to Lead?"

The second is called "Economy".
The same intro, with the type: "McCain on the Economy"
Then twenty-seven seconds of McCain saying "I don't really have the expertise on that" in a variety of forums, including that debate disaster with Ron Paul where he said "I think there should be more sunshine." Also, repeated statements that the economy is strong, fading to black on, "Skip a vacation, take an extra job."
White type over black screen. "Should this man be in charge of the economy? John McCain, Ready to Lead?"

The third is called "Commander in Chief".
You know the pattern. "McCain on Foreign Policy"
Then you've got the "Bomb Iran" clip, Lieberman correcting him about Iran, and then some more clips about Iran and Al Quiada, Czechoslovakia, Mixing up Sunni and Shia, Bombastic comments about Georgia, Russia, North Korea, etc. Then fading out on "There will be more wars, my friends."
White type: Should this man be commander in chief? John McCain, Ready to Lead?"

Of course, this is aimed dead at the low information voter, with a minimum of thought required. The goal, obviously, is to show McCain as a bumbling fool, who knows very little about anything. Thoughts?

in listing the types of diaries and comments we have been seeing the last couple days you forgot one class of diary.

to wit, the ego driven "everyone else just SHUT UP I AM TIRED OF (insert subject here)" type that scold others for concentrating on something the author is tired of seeing, yet the author does nothing to change the subject like writing an interesting diary on some other subject. No, just to scold others because the diarist in question is bored.

If I was as rich as McCain's second wife, I'd make an ad that would demoralize Obama supporters with twisted meaningless poll numbers, deride his credentials, mock his inspirational style, admire McCain's military service, mention the disrespect that Hillary and her supporters have suffered, and end with a motage of losing candidates from the past.

Because if I were as rich as McCain's second wife, I'd want McCain to win, or if I was an idiot.