(Commentary) Even the most emerald of green press secretaries knows this to be true: Tell the candidate to answer the question he wants, not the one she gets.

Rudy Giuliani is taking this basic operating principle of American political debates to another level.

Hizzoner is debating the candidate he wants, not those who are on the stage with him.

In a Republican presidential candidate debate, televised on CNBC in the afternoon Wednesday and later rebroadcast on MSNBC, Giuliani continued to evoke the name of Democratic front-runner Hillary Clinton.

Giuliani’s clear message to the audience: Are any of these guys on the stage with me so compelling, so Reaganesque, that you’d go with what you know in your heart would be their lesser chances in a general election?

Giuliani, the former mayor of New York, drew sustained applause from a Dearborn, Mich., audience when he quipped that if Clinton’s proposed health-care plans become policy reality, “Canadians will have no place to go to get their health care.”

Rudy knows the password to get into the Republican speakeasy and clink political cocktails with the conservatives. Just say “Hillary Clinton” to those suspicious eyes staring back at you through the peering slot and, presto, the door opens. The conservatives may have questions about Rudy, but they have their minds made up about Hillary.

Those lines about “Hillary care” and “Hillary bonds” and the insinuation that she’d even put her own face, the hated countenance, on U.S. legal tender, revs the Repubs.

  “Hillary’s filled with endless ways to spend,’ Giuliani said at one point in the debate.

The Republican debate was the first to feature Fred Thompson, the former U.S. senator from Tennessee.

“I enjoyed watching these fellows,” Thompson said. “I admit it was getting a little boring without me.”

Thompson, a familiar face from the movies and his role on “Law & Order,” came prepared for the economic issues. He’d done his homework and effectively blended statistics dropping, grand philosophical lines and front-porch-swing ease.

“We shouldn’t confuse the wealth of government with the wealth of nations,” Thompson said.

And here’s Thompson on Iraq: The United States can’t “leave with our tail between our legs.”

Thompson showed he belongs on the stage, so in a sense, the day was his.

The arrival of Thompson served mainly to hurt former Massachusetts Gov. Mitt Romney in this debate. Romney, who has what with a neutral eye can be called a substantial record of business and wealth accumulation experience on his resume, should be able to dominate the other Republican candidates in an economics debate.

Romney should have bottom-lined it: compare my net worth with the peasants running against me. We are talking capitalism here and the guy who can go Gordon Gecko should win, right?
What’s more, Romney was in Michigan, with a certain home field advantage as his father, George Romney, served as governor there.

Romney didn’t take ownership of this debate by effectively conveying the most obvious and powerful distinction: he’s the best businessman on the stage.

Romney did hold his own in a one-on-one with Giuliani about which perceived liberal Republican had the best record on taxes and spending in their respective geography, New York City and Massachusetts.

And Romney got off the best one-liners of the debate, book-ending the two-hour debate with them, in fact.

He blamed Michigan Gov. Jennifer Granholm (D) for some of the state’s economic challenges.

“Frankly, I was a little nervous about coming here tonight,” Romney said. “I figured she was going to put a tax on the debate before we got finished.”

And he ripped Thompson near the end, saying the GOP debates were very much like “Law & Order.”

“It’s a big cast. It goes on forever, and Fred Thompson shows up at the end,” Romney said.

As for the other candidates, former Arkansas Gov. Mike Huckabee has hooked his economic thinking to the so-called FairTax. It worked in the Iowa GOP Straw Poll in August but came off as hick  gimmick here.

U.S. Sen. John McCain, R-Ariz., acknowledged the snap of his one-time time rising elevator cable by joking that he was positioned in the “cheap seats” in the debate.

He did make some compelling observations about the economy.

“I think we are in the midst of a revolution we haven’t seen since the industrial revolution,” McCain said, referencing the number of people in the nation who make their incomes based on Internet-related activity.

U.S. Sen. Sam Brownback, R-Kansas, is one of those churchy types who just can’t cross over to the cocktail-and-croquet wing of his party. He comes across as far too corny to be presidential.

I mean, come on, he actually said of the United States of America: “This place rocks.”

Somebody should make Brownback spit out his gum before the next debate.

Texas Congressman Ron Paul, a thoughtful Republican-libertarian, said many things, but since this is Iowa Independent, we need only quote one line: “We can’t be bailing out farmers and subsidizing ethanol.”

And finally there is Colorado congressman Tom Tancredo.
Tancredo literally turned almost every question back on illegal immigration.

That movie “A Day Without a Mexican” is only a preview of the nation Tancredo would like to see, and his repeated references to this issue, his broken-record nasal speech on this, showed him to be one-trick pony we all know him to be.