(CNN) - John McCain has learned his lesson: Don't ever cancel on David Letterman.
Appearing on the late night comedian's show Thursday, the Republican presidential candidate apologized for skipping out on a scheduled visit late last month that Letterman later made the subject of an ongoing joke.
"I screwed up," McCain told Letterman more than once in the interview that's set to air Thursday night.
McCain's appearance on the show comes three weeks to the day after after he raised the ire of the generally mild-mannered host by canceling at the last minute, citing his decision to suspend his presidential campaign because of the financial crisis.
"This doesn't smell right," Letterman said then, during a routine that only half appeared to be a joke. "This is not the way a tested hero behaves. Somebody's putting something in his Metamucil."
Letterman also didn't appear to buy the Arizona senator's explanation for the cancellation then, showing the audience a live feed of McCain preparing for an interview with CBS anchor Katie Couric. After praising McCain's record as a prisoner of war in Vietnam, he said, "This is not the John McCain I know, by God."
Letterman has repeatedly harped on McCain for the missed appearance, noting the Arizona senator's poll numbers appeared to begin to slide right after he skipped out on the show.
"Look at all the conversation I gave you. Including having Mr. Olbermann on," McCain told Letterman Thursday night, referencing the MSNBC liberal talk show host who filled in for him that night.
But Thursday's interview was not all fun and games, as Letterman pressed McCain on Republican VP Sarah Palin's preparedness to lead the country through "the next 9/11 attack.."
"Absolutely" she is, McCain said. "She has inspired Americans. That's the thing we need."
John McCain is not a hero. He is a hypocrite, a liar, and a fraud. Soon, he will be a loser as well.
I know Sarah Palin is a whacky conservative light weight but, dang it, SHE'S SO CUTE!!!
You're just a liar, McShame, and you're getting caught over and over again.
Did anybody count the number of times McCain said the word REFORM in the so called debate?
McCain,72, has decided to leave politics to pusue a degree in theology where he hopes he can become a Bible teacher after he leaves Washington.
Mr. McCain, My friend, You lost this race because you allowed the heathans to alter the core of your person and your pips knowingly screwed you. Simply, You are a Democrat at heart. Blessings to you..
Obama is better for this job at this point and time in history.
Oh I thought he was talking about Sarah Palin!!!!!!!!!!!!!!
Dear John, It's Over. Go home. Signed The American Voters.
Senator McCain is a kind, sincere, experienced statesman who puts country first. Letterman is simply a man trying to be funny.
McCain on CNN, MSNBC at white tie event with Obama-I have three words and one acronym
READING IS FUNDAMENTAL (RIF)
We have to see the big picture:
1. Obama will spend 6 trilling dollars on his all plans which he offers, but where is the money coming from? You know there are only two ways to get the money he needs: increase The Tax and borrow them from somewhere. I don’t think we can borrow any money from China of Japan. So just increase tax is the left way.
2. If Obama going to be the President, Senate, House of Representative, the Supreme Court and the president, all of the administration, our country will be under the Democratic Party. Everybody knew that it is violation of the constitution and it will be too danger.
OMG! McCain was hilarious tonight! I think he just gained 4 points in the election with his comedy!
McCain is just going thru the motion of campaigning. Everybody and their mothers know this elections is already over, and McCain lost big time. It's just a matter of counting the votes, hopefully, accurately THIS TIME!
I here a bunch of people begging for a leader but refusing to do any work themselves.
Congrats... America, you are a nation of whiners trapped by a bed of vipers that are bankers and politicians.
McCain/Palin is nothing more than a completely accurate portrayal of what is wrong with the GOP political theatre: attack ads, racism, lies, elitism, and ineptitude. Yeah John – you screwed up.
Forget McCain. Give us 'Joe the Plumber'. It's entertainment, right?
is cnn going to discuss how McCain said at letterman tonight that criminal c gordon liddy was unrepetent for watergate. This is okay because he served time in jail. hypocricy.
Communist News Network strikes again! When will media in the U.S. not be so left leaning? They praise Osama, I mean Obama all the time.
THE LAST THING AMERICANS WANT IS INSPIRATION FROM AN AIRHEAD...WE CERTAINLY DON'T HER SUCCESSIONIST BELIEFS DURING A NATIONAL CRISIS EITHER!
Can't wait to watch that awkward train wreck!
Vote early or show up early to vote on Nov 4. Nobody is ahead or behind until the last ballot is counted on Nov 4th!! Make sure all your friends and family members get out and vote!!
Yea, McCain screwed up. Kinda tells you how he runs personal business and the business of America. We can't afford to have a screw-up in charge.
Why is that entertainers feel they are like Gods? They are paid to entertain people, to make them laugh, cry, to put on a show. They are like the court jester in the kings court. Get off your high overpaid horses and entertain the public and when your show is over, go home.
John, John, John- Sarah Palin is a empty headed nitwit. We don't need her and we don't want here. She may be the #1 reason you took such a nose dive in the polls once people started listening to her talk!
And somebody needs to tell ol' John that he's not clearing a fighter jet for take-off onboard a carrier-- that gung-ho thumbs up gesture makes him look a little foolish on TV.
Among the many reasons McCain is not a suitable candidate for president, his selection of Palin stands above them all. We could pick most anyone out of a crowd and stand a good chance of doing better than Palin.
It's looking more and more like a McCain win!