6:00 pm ET: Not the most exciting debate of the campaign, but on a day where Fred was going to be the storyline no matter what, Rudy and Mitt provided the battle that will have the most staying power. And here's guessing the conventional wisdom will judge Giuliani the winner, Thompson a close second for not being truly awful. Check back tomorrow morning for a full analysis in The Note.
5:58 pm ET: Thompson gets the last line: "It was getting a little boring without me, but I'm glad to be here now."
5:56 pm ET: Somehow, optimism substitutes for economic policy. Republicans do want to feel good about themselves, but is it enough to just tell them to?
5:54 pm ET: Thompson passes the foreign-leader pop quiz, but it wasn't that hard to just reach north to Canada.
5:53 pm ET: Romney's (extremely scripted) joke is his line of the night: "This is a lot like Law and Order. It has a huge cast, it seems to go on forever, and Fred Thompson shows up at the end."
5:51 pm ET: Reading between the lines here, there's not a lot of love for Rudy on the stage. But he's very optimistic for a man who saw his Yankees blow it less than 24 hours ago: "Get your head up . . . Give me a break: Of course London's not going to replace New York."
5:46 pm ET: "Dangers of a weak dollar?" That's one of those questions sesigned to trip up Thompson, and he wasn't tripped up.
5:40 pm ET: Limping toward the close here, like many of these debates, the highlights came early. Thompson had a better first half than he has second, but the headline's likely to be, Thompson Exceeds Expectations -- which is the benefit of low expectations.
5:31 pm ET: Thompson's in the Screen Actors Guild. Thanks for the reminder.
5:30 pm ET: McCain's been fine tonight, but it seems like nobody's engaging him, and he's not engaging anyone else. Not as strong as his performance last month.
5:23 pm ET: So much for specifics from Thompson on Social Security: "Eating their seedcorn." "Choices are difficult." Something we "have to come to terms with." He's actually talking one of those supposedly tough choices, but he lays it out like it's pain-free. Basically we have to "get our arms around the problem."
5:20 pm ET: Go Sam Brownback: "This place rocks." Now that's real optimism... There's not much upside in the doom and gloom stuff, but we're talking about Michigan here -- a little acknowledgement of economic distress could go a long way.
5:16 pm ET: This is the bad Fred coming through -- all platitudes about the American dream and saying we have to confront our challenges. That's nice, but what does any of that mean?
5:15 pm ET: From ABC's Christine Byun: "Flashback . . . from last week: Thompson visited an ethanol plant last week in Nevada, Iowa, where he donned plastic safety glasses and a hardhat -- and stated that he reversed his position on ethanol subsidies because of national security issues and changes in price."
5:13 pm ET: Katrina, Iraq, and spending -- all wrapped in own bow by McCain. And Romney says no "doom and gloom." Nice encapsulation of their candidacies.
5:11 pm ET: I don't see Romney owning the stage like he has in previous encounters. A bit surprising, since fiscal stuff should be his wheelhouse. But this is still Giuliani's afternoon.
5:09 pm ET: Thompson's first attempt at humor was lame, lame, lame: "I want to explain to my friends here who Goober and Gomer are." Please, tell us.
5:00 pm ET: From ABC's Tahman Bradley: "The last two questions on whether the Iraq war was about oil and whether the president can go after Iran's nuclear capacity has blown Ron Paul's lid and created very memorable lines. "We create money out of thin air and they still accept it as if it's backed by gold," said Paul talking about the 2 trillion dollars the U.S. spends to maintain "our empire overseas." On the issue of Congressional authorization to engage Iran: "You not allowed to go to war without a declaration of war." "
I'd toss it that it got Rudy talking about 9/11 again.
4:59 pm ET: Thompson tells us about the intricacies of the War Powers Act. Who's lazy now, gang?
4:56 pm ET: Again, it's Paul quoting the Constitution -- and getting applause from a GOP crowd by blasting the drumbeat for war in Iraq.
4:52 pm ET: First tough question for Thompson -- and he clarifies his statement about Saddam's WMD. He had the details ready again. Except for his halting answer at the start of the debate, he is looking prepared.
4:51 pm ET: From ABC's Christine Byun: "While it's clear he has done his debate homework, Thompson's answer about the Iraq war borrows his favorite (and most popular) phrases from the campaign stump: "avg 20 yr old knows more than the 20 yr veteran on Capitol Hill;" cant leave Iraq with "the tail between our legs;" the situation in Iraq is a "global war." "
4:48 pm ET: From ABC's Jake Tapper: "The first ad during this CNBC debate, Fred Thompson's first, stars Fred's old cast mate from Law & Order, Sam Waterston . . . for TD Ameritrade. Come to think of it, Maria Bartiromo would make a good Assistant District Attorney. For after Dick Wolf kills the next one off."
4:47 pm ET: Thompson on Iraq -- saying the right things, sounding like McCain, mostly. A pretty non-controversial, non-exceptional answer.
4:44 pm ET: At the first break, this debate belongs to Rudy. And Fred's been solid -- certainly not as bad as he might have been, and he's been snappy in his responses. Giuliani won round one against Romney.
4:40 pm ET: Again, with the off-stage debate -- the Thompson people have sent at least four press releases out so far attacking Giuliani and Romney. Interesting that nobody's trying to take on Thompson on stage.
4:37 pm ET: Spoke too soon -- Duncan Hunter doesn't want Dubai here. Neither does Tancredo.
4:35 pm ET: Huckabee again in a call to arms to the GOP base. "We're going to get our britches beat next year" if the party doesn't change.
4:34 pm ET: Giuliani lets a Dubai company buy 20 percent of NASDAQ and nobody bites. Count me as surprised.
4:31 pm ET: From Bret Hovell: "Back on track? McCain's second answer - which got applause like his first - was better. He was able to use some lines he's practiced on the stump, including the number of people who make their living on eBay and the joke about the DNA of bears, which lent itself to a smoother delivery."
4:29 pm ET: Lest anyone forget why Tancredo's running for president...
4:28 pm ET: ABC's Matt Stuart, who covers the Romney campaign for ABC: "Romney did not look too happy that Giuliani got the last word in that back and forth."
4:27 pm ET: From ABC's Jake Tapper: "This is the first time Rudy Giuliani has directly taken on an opponent. Giuliani criticized Romney for spending and taxes going up in Massachusetts while Romney was governor, while they went down while Giuliani was Mayor in NY. "It's a nice line, but it's baloney," said Romney. Responded Giuliani on the line item veto charge, "Youâ€™ve gotta be honest with people." Until this afternoon, Giuliani has largely refrained from criticizing his GOP opponents.
4:23 pm ET: Here it gets good -- these pair of blue staters going at it on taxes spending. The first great line on the night, from Rudy: "I led, he lagged." And a great defense of suing over the line-item veto: "You can bang your head against the wall all you want" -- but it's still unconstitutional.
4:19 pm ET: Tom Tancredo brings up the "third rail" of entitlement spending. Here's betting nobody else mentions private Social Security accounts if they have anything to do with it.
4:17 pm ET: Sounds like Fred Thompson was ready to go today. He looks and sounds solid -- and dare I say, confident.
4:15 pm ET: From Bret Hovell, who covers McCain for ABC: "McCain looked and sounded confused in his first answer. When he couldn't hear Maria Bartiromo's follow up, he looked kind of out of it, I thought. I also don't think he really answered the question."
4:14 pm ET: Mike Huckabee is the first to speak real directly about economic distress. And the fair tax crowd gives Huckabee something of a base of support.
4:13 pm ET: The shadow debate (off-stage) continues. From Giuliani's campaign: "MASSACHUSETTS DURING ROMNEYâ€™S TERM WAS MARKED BY ECONOMIC STAGNATION."
4:11 pm ET: Anyone else think McCain looks better tonight than he has in previous debates? Maybe he likes the hour, or the mini-boost in momentum for his candidacy?
4:09 pm ET: Don't forget that Ron Paul has plenty at stake tonight, too. People are paying attention to him because of his fund-raising haul. "It's always the poor people ... that suffer the most." And then he hits the "military-industrial complex." Not sure this plays with the GOP base. Sounds like John McCain doesn't think so.
4:07 pm ET: Rudy Giuliani starts by quoting Hillary and acknowledging the Yankees. Man, these guys came in like football teams who script their first 10 plays. And he's keeping Joe Torre! That may cut into his base of support among Yankee fans.
ABC's Christine Byun offers this "pin watch": "Thompson's wearing his flag pin - which he wears sometimes - not all the time - on the campaign trail. Romney is not wearing his pin."
4:05 pm ET: Michigan native Mitt Romney is the first to make it local -- and the Michigan economy is an unmistakeable backdrop this afternoon. "To the auto industry: the door's always open." Take that, Barack Obama! And a Romney canned line: "I figured [Gov. Jennifer Granholm] was going to put a tax on the debate before we got finished."
4:03 pm ET: Fred Thompson gets a shot right out of the chute: "There is no reason to believe that we are headed for a recession." Lots of specifics, lots of numbers -- notwithstanding what some economists are warning about. Then he turns it to fiscal discipline. Not a bad start. "We are enjoying a period of growth right now. We should acknowledge what got us there."
3:58 pm ET: In case you're wondering about what to expect from this storyline, the Romney campaign sent this press release out eight minutes BEFORE the debate started: "GIULIANI SUPPORTERS PRAISE GOV. ROMNEY'S FISCAL RECORD." But here we go, at this very odd hour for a presidential debate.
This from ABC's Bret Hovell, who's at the debate in Michigan: "Debate press room is a basketball court - nice hardwood floors - rows of folding tables covered with white tablecloths. Six flat panel monitors display the debate for the press. Posters hanging around the room include one for Chrysler, American Arab Chamber of Commerce, Your Money Your Vote - CNBC, Ford. There's a huge disco ball hanging from the ceiling. It really is one of the larger disco balls I've ever seen. I think after the debate we're going to have a prom."
Rick Klein here, author of ABC's The Note. I'll be blogging during this afternoon's Republican debate, starting at 4 pm ET, with contributions from other ABC reporters. Be part of the conversation, as we all wait to see whether this actor knows his lines (or insert the theater cliche of your choice).