Walker seems like a nice guy - I was actually an early proponent of him running for the top job, probably still am.
However, recently he has been wobbly on too many issues of concern. Conservatives have been sidelined and thrown under the bus too many times by the caving repubs. If conservatives go only with people who have been declared by liberals as "being able to win", conservatives will win nothing.
The best all round conservative is Ted Cruz - fiscal, social, libertarian. He does not kowtow to GOPe leadership, the chamber of cronies, or the liberals.
Ted Cruz is very smart, articulate, and has personal charisma. He is able to deal with the national liberal media and the democrats.
With Ted, conservatives don't have to be worried about being thrown under the bus. He will move the needle for conservatism. Everything else is fluff. Party labels don't mean much.