COLUMBUS, Ohio — The grandson of U.S. President Warren G. Harding and his lover, Nan Britton, went to court in an effort to get the Republican’s remains exhumed from the presidential memorial where they have lain since 1927.James Blaesing told an Ohio court that he is seeking Harding’s disinterment as a way “to establish with scientific certainty” that he is the 29th president’s blood relation.The dispute looms as benefactors prepare to mark the centennial of Harding’s 1920 election with site upgrades and a new …