Do president-picking homework

In this July 22, 2014 file photo, A "Vote Here" sign is seen outside the main entrance to the Fleming Park Bernie Ward Community Center during a run-off election day in Augusta, Georgia. (AP Photo/The Savannah Morning News, Sara Caldwell)

The presidential race is a marathon, not a sprint. And it will be running through high-stakes South Carolina primaries before month’s end.

So don’t jump to a premature-finish-line conclusion over Texas Sen. Ted Cruz’ victory in Monday night’s Iowa caucuses, which generated a record Republican turnout.

Remember, Mike Huckabee won that heartland contest in 2008, then Rick Santorum triumphed there in 2012, and neither captured the GOP nomination.

Sen. Cruz’ margin of victory over Donald Trump was a mere 28 to 24 percent. But the Lone Star State maverick’s triumph confirmed that he’s a formidable contender riding major momentum as the chase heads to the Feb. 9 New Hampshire primary.

Conversely, “The Donald” badly needs to win that next outing to reassert his national front-runner status.

Meanwhile, though Democratic front-runner Hillary Clinton edged Vermont Sen. Bernie Sanders in Iowa (or did she?), their virtual tie demonstrated anew that her once-seemingly smooth path to the nomination has become quite bumpy. Sen. Sanders holds a substantial poll edge in New Hampshire; Mrs. Clinton leads him by a large margin in our state.

However, the Iowa caucuses’ biggest game-changer was Florida Sen. Marco Rubio’s surprisingly strong third-place finish with 23 percent of the vote, barely trailing Mr. Trump.

That outcome appears to make this, at least for now, a three-way GOP race, not just a one-on-one battle between Mr. Trump and Sen. Cruz. As for other members of the still-crowded GOP field, they all ran far behind the top three in Iowa, reflecting their long-shot status.

Sen. Rubio got more good news Tuesday with an endorsement from South Carolina Sen. Tim Scott. That should enhance Mr. Rubio’s chances, and not just in the Feb. 20 S.C. GOP primary.

That event, and then the S.C. Democratic primary on Feb. 27, should give Palmetto State voters a significant say in who becomes our next president. With that opportunity comes the obligation to cast an informed ballot.

Brace yourself for a barrage of campaign commercials.

Yet also extend your focus on this competition beyond those propaganda pieces and learn more about the candidates by watching looming debates before you must make your primary call.

The Democrats, now down to just Mrs. Clinton and Mr. Sanders with Monday night’s withdrawal of Martin O’Malley, debate again on Thursday night in Durham, N.H., and on Feb. 11 in Milwaukee. The Republicans, minus Mr. Huckabee, who like Mr. O’Malley dropped out after a dismal finish in Iowa, will debate in Goffstown, N.H., on Saturday night and in Greenville on Feb. 13.

After all, no offense to the president pickers in Iowa and New Hampshire, but more people now live in South Carolina than in those two states combined.

And considering the fluid — even chaotic — states of both parties’ nomination fights at this point, South Carolina will likely have a bigger impact on the presidential race, too.