Sen. John Thune, R-S.D., has hired Joshua Shields to be his campaign manager, the aide confirmed to CQ Roll Call Tuesday.  

Shields is a South Dakota native who worked on Thune’s 2002 and 2004 races and in his Senate office.  

In 2010, he was the campaign manager for Rep. Kristi Noem, R-S.D., in her first bid for Congress against former Rep. Stephanie Herseth Sandlin.  

Herseth Sandlin, now in the private sector, was considered a top Democratic contender for the open Senate seat in 2014, but opted against a run. She would be on a short list of candidates for Democrats against this year.  

So far, no Democrats (or Republicans) have indicated interest in challenging Thune. But his team is ramping up as though he were facing a competitive challenge. The senator has not yet officially announced his re-election bid, and Shields said there are no imminent plans to do so. But Thune started the year with a $9.7 million campaign war chest  — the second highest sum of any Republican incumbent. A source familiar with Thune’s fundraising said he will finish the first quarter with $10.3 million, leaving little doubt about his plans.  

One potential challenger is former U.S. Attorney Brendan Johnson, son of former Sen. Tim Johnson, D-S.D. The younger Johnson was considered a possible candidate when his father retired in 2014, but was prohibited from engaging in political activity in his official role. Now that he has resigned , he could choose to run.  

Democrats need to gain five seats in 2016 to secure the majority, but Republican-leaning South Dakota would be an uphill battle. The race is rated Safe Republican by the Rothenberg & Gonzales Political Report/Roll Call.  

Correction 12:45 p.m. An earlier version of this post misstated the date of confirmation of the hire.  

Related:

Brendan Johnson Discusses His Future in South Dakota

Senators Confirm Re-Election Bids for 2016


Stephanie Herseth Sandlin Not Running for Senate


Quirky Ex-Senator Stomps on Democrats’ S.D. Hopes


Rothenberg & Gonzales Political Report/Roll Call 2016 Race Ratings


The 114th: CQ Roll Call’s Guide to the New Congress


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