For a candidate known for one of the past decade’s most colossal political mistakes, former Gov. Mark Sanford has run a nearly flawless campaign for the 1st District.

As a result, Sanford is on track to win the Republican runoff and maintains a solid position in the special election for the coastal, GOP-leaning district.

On Tuesday, voters will determine whether Sanford can proceed with his political comeback over his GOP opponent, attorney Curtis Bostic. Palmetto State Republicans are confident Sanford will win the GOP nomination and continue to face Democrat Elizabeth Colbert Busch in the May 7 general election.

A runoff victory will show that even after the former governor’s epic political implosion — disappearing from the state for days and admitting to an extramarital affair with a woman from Argentina — solid campaign mechanics can push a candidate to victory.

“The governor has spent plenty of time addressing his personal failures from 2009, and I think anyone who knows him would agree that it was very much at odds with the rest of his political career,” Sanford spokesman Joel Sawyer said in an interview.

Sawyer is one of a handful of former Sanford aides helping their previous boss on his quest for political redemption. That path lies in familiar territory: Sanford used to represent much of the current 1st District in Congress before he became governor.

His campaign’s competence there contrasts with Bostic, who struggled with organization and fundraising during the primary. For example, Sanford has aired television spots, but Bostic’s ad buys are minimal.

Instead, Bostic touted endorsements from noteworthy conservatives such as former Pennsylvania Sen. Rick Santorum, commentator Ann Coulter and others. Bostic’s supporters portray him as the anti-Sanford. They note his integrity and faithfulness — a not-so-subtle jab at Sanford’s affair and subsequent divorce.

Sanford supporters counter that 1st District voters prize fiscal conservatism over social issues.

But while many South Carolina Republicans are certain Sanford will win Tuesday, their opinions are more mixed about the general election. Some say the math absolutely does not add up for a Democratic takeover of a solidly Republican seat. Others are not as confident.

On Monday, Colbert Busch’s campaign released a poll showing her to be competitive, but it is unclear whether those numbers will hold against Republican attacks.

What really scares some Republicans is her brother, comedian Stephen Colbert, and his television and online following. He has 4.7 million followers on Twitter.

“Of all the districts in South Carolina, if there is one Republican [seat] … a Democrat could take, it’s this one,” said a South Carolina GOP operative and Sanford ally. “Sanford’s going to have to fight tooth and nail.”

This is an open-seat race to succeed Republican Tim Scott, who was appointed to the Senate.

The polls close at 7 p.m. for the runoff.