Former Arkansas Gov. Mike Huckabee (R) is endorsing Rep. James Lankford (R-Okla.), giving him a potential boost with social conservatives in his Senate primary.
Lankford is facing Oklahoma House Speaker T.W. Shannon (R) in the primary to replace retiring Sen. Tom Coburn (R-Okla). Shannon is trying to run to Lankford's right and has locked up endorsements from former Alaska Gov. Sarah Palin (R) and the Senate Conservatives Fund.