Memo to Rick Santorum of Pennsylvania, Mike Pence of Indiana, and John Thune of South Dakota, and perhaps to Butch Otter of Idaho, too: It’s time for you gentlemen to run for president.

Yes, of the United States. Yes, this year.

Here’s the situation: Mainstream conservatives are being routed in this year’s presidential contests. And if John McCain or, less likely, Mike Huckabee goes into the Republican National Convention in Minneapolis with a first-ballot majority, the conservative movement will be completely shut out of a general election presidential campaign for the first time since 1976. For the movement that has brought peace, triumph and prosperity to this nation for 27 years, such an outcome would be a disaster — and, worse, it would be a disaster for the country.

But there’s a way to fight back. A way to ensure clout at the convention, and perhaps still to find a way for a real conservative still to get the nomination. The way to do so is to force an open convention — a convention where nobody enters the proceedings with enough pledged delegates to secure the nomination, and thus where the delegates actually must deliberate, and perhaps engage in several rounds of balloting, before a victor emerges.

The way to force an open convention is for conservative candidates to amass delegates pledged to themselves rather than to McCain or Huckabee. And the way to do that is by reviving the old stratagem of the “favorite son” candidacy. Rather than having a candidate try to run nationally, a candidate can compete just in his own home state. Win the state, or at least a majority of the delegates thereof, and you go to the convention with some bargaining power.

The filing deadlines for presidential primaries or caucuses in seven states, boasting 285 convention delegates, occur after Super Tuesday. Mega-state Pennsylvania, with 74 delegates, allows candidates to qualify up until Feb. 12. The filing deadline in South Dakota isn’t until March 25. If favorite sons run and win in all those states, and if Mitt Romney continues to fight McCain and Huckabee throughout the primary season, then the favorites sons could, collectively, hold the balance of power at an open convention.

IN RECENT WEEKS, Pennsylvania’s former Sen. Santorum has gone on a tear in criticizing his former colleague McCain. He has been saying that behind closed doors in the Senate, McCain consistently fights against even allowing floor consideration for conservative issue after conservative issue. Well, here is Santorum’s chance to block McCain: Qualify for the presidential primary in Pennsylvania, fight a hard campaign, and win it.

Thune should do the same for the South Dakota contest. Pence should do the same for Indiana. Keenan and Otter should do the same in their states. And a leading conservative should take the plunge in Nebraska, New Mexico, and Oregon, too.

Cynics will say it would never work. By the time Pennsylvanians vote on April 22, they will say, the race will be over.

Maybe, maybe not. Here’s the thing: Nobody has tried something like this for such a long time that the very newness of it, and the uncertainty, could keep the race alive. A candidate who loses most races on Super Tuesday, but who still garners significant delegates, might be encouraged to remain in the race rather than drop out. Pundits will have such a field day speculating about whether a series of favorite-son candidacies could work that the speculation itself would have the effect of stopping the tendency toward a premature coronation of a front-running candidate before nearly half the country has even voted. And candidates who have already dropped out might even be encouraged to reconsider. With a new paradigm at work, they might figure, just about anything could happen.

In that light, Fred Thompson ought to announce that he is asking Tennessee Republicans to vote for him after all on Super Tuesday. Tell them he wants to be his home state’s favorite son, in order to carry a conservative message and some conservative bargaining chips to the national convention. And if Thompson really had gumption, he could tell Virginians voting on Feb. 12 that they should consider a vote for him to be the equivalent of a vote for a favorite-son candidacy of his friend and supporter George Allen, to whom he would publicly cede any delegates Thompson might win that day.

And so on. Party rules allow delegates to vote for any candidate they choose (subject to various state laws), regardless of whether the candidate is formally nominated. The greater the number of favorite sons who announce candidacies or surrogate candidacies in their respective states, the more uncertainty there would be. In this case, uncertainty would be a good thing. An open convention would be a good thing. It would garner unprecedented TV attention.

The sight of actual, old-style, person-to-person, republican government in action could enthrall a nation of voters made cynical by modern media campaigns. Here, they would see, ordinary citizens participating in the process, rather than professional politicians, would actually be making decisions that mean something for the future of their country.

BUT WHY, ONE MIGHT ASK, should conservatives go to such trouble?

Because conservatives ought to be horrified by the prospect of John McCain winning the nomination without first needing to earn our votes at a convention rather than merely being ceded those votes by default.

Because John McCain disdains the conservative movement. Because he has a temper so volcanic that Democrats could easily bait him into a “Howard Dean moment” in the fall that ruins his campaign and hands a landslide to either Hillary Clinton or Barack Obama. Because McCain has run an entirely dishonorable, mendacious primary campaign so far. Because, from a conservative standpoint, McCain is bad on border security, bad on taxes, bad on judges, bad on respect for the letter of the Constitution, bad on respecting those who disagree with him, bad on energy exploration, bad on free-market economics, and absolutely horrendous in his zealous support for excessive regulation. He hearkens back not to Ronald Reagan’s principles but, quite openly, to Teddy Roosevelt’s — and the truth is that TR was a big-government interventionist with an authoritarian streak and an out-of-control ego. Just like McCain is today.

McCain might still win an open convention…but in an open convention at which conservatives hold the balance of power, almost anything could happen. At the very least, McCain would be forced to take active steps to make conservatives part of his team rather than shutting them out. He could be forced to choose a vice presidential nominee more amenable to the conservative movement. And he might still be defeated.

Thompson could re-emerge as a compromise, consensus choice. Or Dick Cheney. Or Jeb Bush. Or SEC Chairman Chris Cox (also a perfect VP choice for just about anybody). Or one of the favorite sons themselves; I can think of far worse general-election scenarios than a Republican ticket led by Thune, Santorum, or Pence.

Sen. Santorum, the first move is yours.