Well, I have claimed to be a social liberal and a fiscal conservative since about the mid-70s, and I think I can explain so that you at least don't consider it an impossibility and it even might make you like him better!
As a social liberal, I hold a LOT of the liberals' pet beliefs. A quick explanation is that I support the BoR, although somehow your average liberal only manages to support 9 of 10. I believe government should stay out of the religion business, the accused should have rights, children are important, a black man has the same rights and abilities and freedoms and protections as a white man, you name it.
As a fiscal conservative, I think gubt should tax less, spend less, and use deficit budgeting solely to stimulate the economy, which would normally be accomplished by cutting taxes during recessions and raising them during booms, a function relegated to Alan Greenspan and interest rates now because he's the only one with the stones to do the job without fear of the ballot box. I believe throwing money at problems doesn't solve them, freedom does. So my solutions to problems normally do not include spending billions on them.
Maybe the confusion comes from not being able to distinguish anymore between the actions/wants/proposals from liberals and conservatives except in the areas of religion and gun control.