Welcome back, Mark Sanford.

The former South Carolina governor will soon return to Washington, D.C., having pulled off an improbable political comeback, winning South Carolina's First District special election against Democrat Elizabeth Colbert Busch, after his 2009 Argentinian affair scandal knocked his star out of the Republican Party's sky.

Sanford will take back the seat he represented in the 1990s, making his return to Washington and serving in the House again for the first time since January 2001.

But how will Sanford's own party welcome him back?

The National Republican Congressional Committee pulled its support for Sanford after allegations arose that he trespassed on his ex-wife's property on Super Bowl Sunday (and in previous years, after their divorce).

"Mark Sanford has proven he knows what it takes to win elections. At this time, the NRCC will not be engaged in this special election," NRCC spokeswoman Andrea Bozek told ABC News on April 17, after the allegations surfaced.

House Speaker John Boehner, who had endorsed Sanford before the trespassing allegations were reported, sounded less enthusiastic about the former governor's possible return to Congress when asked about him at a press conference this week.

"Just like any one of us or any of the 435 members of Congress, we don't get to choose who they are," Boehner told reporters on Tuesday, as voters were voting in Charleston, S.C. Their electorate gets to decide, so we'll see what the outcome is today."

But Republicans appear to be warming up to Sanford, now that he's won.

NRCC Chairman Greg Walden, a representative from Oregon, called Sanford to congratulate him and has been trading voicemails with the congressman-elect, according to an NRCC official.

"Congratulations to Mark Sanford for winning tonight's special election. These results demonstrate just how devastating the policies of Barack Obama and Nancy Pelosi are for House Democrats in 2014," Walden said in a statement posted to the NRCC's website. "Democrats spent more than $1 million trying to elect a candidate who was backed by the Democrat machine, but at the end of the day, running on the Obama-Pelosi ticket was just too toxic for Elizabeth Colbert Busch."

Sanford, as he promised voters, will enter the House having retained his seniority, having already served for six years, from 1995 - 2001, a House aide confirmed to ABC News. He won't leapfrog ahead of members who've served continuously, and he'll take a backseat on committees to those with the same number of years' experience, but even though Sanford enters as a potential albatross for Republicans (if Democrats have their way, in tying the party to his 2009 scandal), he won't be the new kid on the block in GOP conference meetings.