Blankenship maintains his innocence and has appealed, unsuccessfully, to have his conviction overturned. While in prison, he wrote a 67-page booklet in which he said he was an "American political prisoner" and distributed 250,000 copies. On his blog and in the booklet, he blamed the U.S. Mine Safety & Health Administration for the blast.
His longtime adversary, Democratic Sen. Joe Manchin, is running for re-election. But Blankenship is in a Republican primary with U.S. Rep. Evan Jenkins and West Virginia Attorney General Patrick Morrisey.