Make the top GOP three in S.C. or bust?

Jeb Bush points out a relative in attendance, his uncle Jonathan Bush, during a campaign stop in Mount Pleasant, S.C. on Ash Wednesday, Feb. 10, 2016. (Stephen B. Morton/The New York Times)

In South Carolina’s Republican primary, a lot rides on second and third place, as it did in New Hampshire.

Put differently, the fourth- and fifth-place winners may be not be able to hang on much longer.

South Carolina is a more populous state than Iowa or New Hampshire. That means a lot more traveling around (Donald Trump may have to forgo sleeping at home) and more reliance on paid and earned media.

You cannot win the primary in which 600,000 Republicans will turn out simply through town halls and coffee-shop visits.

The favorite going into South Carolina is unquestionably Trump, who comes off a huge win in New Hampshire. His populist brew of protectionism and patriotism may play well in the less affluent areas of the state, especially in the Upstate, where Mike Huckabee did well in 2008 and Newt Gingrich cleaned up in 2012. Trump will need to compete with Sen. Ted Cruz, R-Texas, for evangelical voters, as he did in Iowa.

One hitch for Trump is his reliance to date on independent voters; a great number of those will wait to participate in the hotly contested Democratic primary coming up on Feb. 23. That may help Cruz and/or Sen. Marco Rubio, R-Fla.

In the more affluent Lowcountry area and in the state capital of Columbia and surrounding suburbs, Jeb Bush and Rubio have their best shot to knock out the other one to grab third or even second.

Those areas, when combined with votes from elsewhere, could give one of them a strong showing. They are both counting on Ohio Gov. John Kasich’s more liberal bent (e.g. expanding Medicaid) and shaky national security record to marginalize him in the state.

We have seen before how the political geography plays out in South Carolina primary races. Recall that in 2012, Romney picked up nearly 13,000 votes in Richland County (which includes Columbia) and dominated in the Lowcountry. However, outside of those areas, he did not win a single county. He lost the state to Newt Gingrich, who did well enough in those areas, and then dominated elsewhere.

In 2008, by contrast, McCain won the Lowcountry and Richland County, but also extended his reach up the eastern coast to the Pee Dee region, through the Midlands and into a couple of the Upstate counties. (He collected a healthy share of the vote in Greenville and Spartanburg, although did not win either.) That was enough for 33 percent of the vote and a McCain victory in essentially a four-person race (against Huckabee, Romney and Fred Thompson).

Trump and Cruz will be fighting to duplicate Gingrich’s success in 2012. If they divide the vote, however, one of them might get passed by Bush or Rubio, who will be collecting votes from areas where McCain did well in 2008 and where Romney picked up votes in 2012.

As between Rubio and Bush, the one who comes in behind the other will be under tremendous pressure — if there is a significant difference in their performance — to get out of the race.

Republicans convinced that Trump or Cruz would be a disaster for the party want a single candidate, one broadly acceptable to the “somewhat conservative” and moderate GOP electorate, who can then face off against Cruz and Trump. They will certainly have their man if Bush or Rubio grabs second place in South Carolina, beating out the other Floridian plus Cruz.

If Bush and Rubio finish neck-and-neck as they did in New Hampshire, however, they likely both go on to Nevada’s caucus just three days later.

Many Republicans are understandably anxious to find a single mainstream candidate. That will take time, however.

With each candidate who drops from the race, the consolidation of non-Trump voters moves along. It is not necessary to settle on a single not-Trump competitor before Super Tuesday, or maybe until March 15, when the winner-take-all state races begin.

South Carolina is just one more step in that process.

Jennifer Rubin is a columnist for The Washington Post.