McVeigh was intensely interested in the 2nd Amendment, which put him squarely on the right. He was a military man who railed against what he called the tyrannical federal government. He was outspoken in his criticism of the Clinton's Waco Seige, specifically the government's trampling of the first amendment (the religious rights of the Branch Davidians; the right to peacefully congregate) and the second amendment (their right to bear arms as a form of protection from a tyrannical government).
Tim McVeigh was categorically and self-admittedly on the Right. He was among the first wave of Rightwing Americans to be infected by talk radio, which prodded unstable people with poor educations to "take their country back".
McVeigh's mass murder was pure Rightwing Terrorism. He followed Rightwing ideology to its rational conclusion, which mandates that citizens take their country back by force if necessary.