COLUMBIA, S.C. — Sen. Lindsey Graham will challenge a subpoena ordering him to testify in front of a Georgia grand jury investigating possible criminal interference in the state’s 2020 election. The South Carolina Republican has hired Charleston attorneys Bart Daniel and Matt Austin, of the Nelson Mullins law firm, according to a statement Wednesday that called the subpoena by the Fulton County grand jury “all politics” and part of a “fishing expedition” to share information with the U.S. House committee investigating the Jan. 6 Capitol riot. Graham’s been called to testify July 12. ”In my con…