For 30 years, South Carolina Republicans have demonstrated moderation in their presidential primary. Their pick has become the eventual nominee every year since the primary's inception in 1980 and when given a stark choice, they have always selected the more centrist candidate.

That all came to an end Saturday. By backing Newt Gingrich, Palmetto State voters tossed tradition aside and threw a major roadblock into Mitt Romney's stroll to the Republican nomination.

It was a misguided choice, for their party's electoral chances and for the nation's prospects. If Republicans nationally follow South Carolina's lead, they will nominate a man with a pullcart full of baggage.

South Carolina on Saturday voted for a man who:

Admits to cheating on his wife at the same time he was attacking Bill Clinton over the Monica Lewinsky affair.

Was fined $300,000 in an overwhelming, bipartisan House vote for ethics violations.

Was challenged by fellow Republicans three years into his leadership, and eventually resigned from the House.

Took $1.6 million from Freddie Mac.

Sparks fears in many Republicans, who never know what explosive thing he'll say next.

All that likely makes a Gingrich nomination disastrous for Republicans' hopes of taking back the White House. But if Obama's own shortcomings and a stagnant economy combine to produce a Gingrich presidency, it portends more of the polarization that has paralyzed our nation's public affairs.

We sympathize with Gingrich backers who worry that Romney's not capable of bringing about the change the nation requires. America's economy is entering its fifth stagnant year, our debt tops $15 trillion and special interests have taken the Capitol hostage. If the United States needed hope and change in 2008, circumstances desperately call for it now.

Even so, South Carolina's vote for Gingrich is another too-far swing of the pendulum that threatens to keep the country gridlocked by extremism, with problems that only get worse with every day they are not confronted.

Democrats and Republicans each have an unfortunate and self-defeating penchant for misreading voters' messages. They mistake an electoral victory as a mandate for extreme ideological approaches to public policy, when usually it is just the opposite: a repudiation of that exact approach by the party in charge.

America's challenges need bipartisan solutions. And while it might feel good to "send a message," the country needs statesmanship to trump ideological fervor and love of country to trump blind adherence to party.

By backing Gingrich, South Carolina voters showed they get more gratification from sending the message than from helping the country right itself.