This article is from the archive of our partner National Journal

Former Sen. Rick Santorum of Pennsylvania and his Patriot Voices PAC will endorse South Dakota Republican Mike Rounds in his bid for the Senate on Tuesday, a Santorum aide told National Journal, joining national Republicans in boosting the GOP candidate in the wake of renewed interest in the race.

The endorsement will be announced later this morning. Santorum, who has endorsed a spate of GOP candidates in competitive races this year, is slated to speak at a nonpolitical dinner event for the Family Heritage Alliance in Rapid City, S.D.; before that, Rounds will join Santorum for a press conference nearby.

"We need commonsense, Midwestern values in the United States Senate, not more power in the hands of Harry Reid," Santorum will say in a statement. "As governor, Mike Rounds was a proven job creator, and he will go to Washington to stop Obamacare and stand up for life."

South Dakota had long been seen as a near-automatic pickup for Republicans, with Rounds generally holding double-digit polling leads over Democrat Rick Weiland and Republican-turned-independent candidate Larry Pressler.

But national Democrats announced last week that they would pour $1 million into ads there, suggesting they think the race has some promise. Republicans countered by investing $1 million of their own into the race for the final weeks before Election Day. A fresh poll from the GOP-aligned Harper Polling released Monday found Rounds leading Weiland by just 4 percentage points, 37 percent to 33 percent, with Pressler in third place with 23 percent.

Santorum joins the National Republican Senatorial Committee in putting support behind Rounds, suggesting both that national Republican groups and figures will work to keep Rounds in the lead hereā€”and also that he may need that help in the first place.

Following his stop in Rapid City, Santorum will travel to Iowa to participate in a series of events for the Iowa Faith & Freedom Coalition.

This post was updated to correct a link.

This article is from the archive of our partner National Journal.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.