Mitt Romney passed the likeability test at the first presidential debate on both an absolute and a relative basis. It wasn’t even a contest between the Republican nominee and the Barack Obama impersonator who showed up to play the president in Denver on Oct. 3.

At the second, town-hall debate on Tuesday, it was the feisty Obama who took to the stage to level accusations at Romney and fend off counterattacks. If the public could glean anything more than a to-do list from either candidate — the how-to list comes later — my congratulations.

Last week, I revealed some of the Democrats’ secrets.

RELATED ITEM Five things the Democrats won’t tell you »

Now it’s the Republicans’ turn. Here are five things they don’t want you to know.

No. 1: Romney isn’t a true conservative.

Democrats can’t decide if Romney is a flip-flopper, a centrist or “severely conservative,” as he described himself. Neither can Romney.

I’d bet against “severely” for the simple reason that “governor of Massachusetts” isn’t a conservative credential. The state is among the bluest of the blue, voting for the Republican presidential candidate only four times since 1928: twice for Dwight Eisenhower and twice for Ronald Reagan. Yes, Massachusetts has had its share of Republican governors, including William Weld (1991-1997) and Romney (2003-2007). But in general, the Bay State prefers its conservatives “lite.”

As governor of Massachusetts, Romney was for a woman’s right to choose before he was against it. Ditto reducing greenhouse gases. His signature achievement? Universal health care, complete with an individual mandate.

Romney veered right during the primaries before tacking to the center during the first debate. Romney the centrist did better in the polls. A centrist president would be a disappointment to the Tea Party, which came to see Romney as its best shot to defeat Obama.

Social conservatives might find themselves on the sidelines, as well. If elected, Romney will face so many fiscal cliffhangers that overturning Roe v. Wade will be the last thing on his mind — and his agenda.

No. 2: Don’t hold your breath on those loopholes.

Much of the criticism of Romney’s tax-reform plan is directed at his budget math. Romney wants to lower corporate and individual income-tax rates and do away with the estate and alternative minimum taxes. He says he will make up the lost revenue by closing loopholes. And he will do all of this without adding to the deficit, raising taxes on the middle class or changing the progressivity of the tax code. Good luck with that.

Romney’s critics want to know exactly which deductions and exemptions he plans to eliminate, but he’s not telling. Why? Because he isn’t going to get rid of entire categories of loopholes since each one has a powerful (read: voting) constituency behind it.

Imagine a candidate running on the following platform: “Vote for Mitt Romney and kiss your mortgage-interest deduction goodbye!” It sounds like a negative campaign ad, and would probably have the same effect.

Romney has said clearly — apparently not clearly enough — that he will limit the amount of deductions that high-income earners can take while preserving them for the middle class. He also said at the first debate that he wouldn’t implement a tax cut that adds to the deficit.

Eliminating all the loopholes in the tax code, including the mortgage deduction and exemption for employer-provided health care, would generate $1.3 trillion of revenue annually, according to Congress’s Joint Committee on Taxation. Now you’re talking real money. You’re also talking pipe dream.

No. 3: A big tent is better than a small lean-to.

Whatever happened to the Grand Old Party? Who folded Ronald Reagan’s Big Tent, which could accommodate Arlen Specter and Rick Perry, Olympia Snowe and Michele Bachmann? Nowadays, RINOs — Republicans in Name Only — aren’t welcome.

Polls confirm that the U.S. is still a center-right nation. Surely Republicans understand that center-right is left of hard- right. So many people are turned off by conservatives’ hard-line positions on gay marriage and abortion, they vote Democratic on that basis alone.

Centrist Republicans, like centrist Democrats, are a dying breed. If the Republican Party is to survive, it may need to update its philosophy for the 21st century. The party that wants to ban government from the boardroom should think twice before inviting it into the bedroom.

No. 4: Made in America isn’t made for Americans.

Politics and trade make lousy bedfellows. Everyone remembers when free-trader George W. Bush succumbed to politics and slapped tariffs on various steel imports in 2002 to help domestic producers — not to mention his re-election prospects in certain steel-producing states.

Romney has accused Obama of being a wuss when it comes to China’s unfair trade practices and says he will declare China a currency manipulator on day one, the first step in imposing tariffs on imports.

Bad idea, and Romney knows it. And not because China will dump its dollars — dollars that are the byproduct of its exports to the U.S. Protectionism hurts consumers, who end up paying higher prices. Centuries after the benefits of free trade were outlined by David Ricardo and Adam Smith, politicians are still drawn to the magic of mercantilism.

No. 5: About that pledge never to raise taxes…

One of the more memorable moments of the Republican primary debates took place at Iowa State University on Aug. 11, 2011. The moderator asked the eight candidates if they would reject a deal that included $1 of tax increases for every $10 of spending cuts. All eight raised their hand.

Everyone who knows or has worked with Romney talks about his strengths as an executive, his ability to get things done. As chief executive of USA Inc., if Romney had a deficit-reduction agreement on the table with a 10-1 trade-off, I bet he would take it and double down.

Four years ago, I penned a pair of “Five Things” columns. Reading them today, it appears little has changed: The dates and names may be different, but the issues are still the same. I suspect that will be true four years from today.

–Bloomberg News–

(Caroline Baum, author of “Just What I Said,” is a Bloomberg View columnist. The opinions expressed are her own.)