There are lots of differences. Check harrybrowne.org, and click on "articles by Harry Browne" on the left hand side, and read the republican article he has. They are really eye opening. (sorry can't supplly direct links, because of the site layout)
There stance on drugs, is that the gov't should have no control over peoples lives. Even if you think they should, the war on drugs is a lose-lose battle. It causes problems, and has VERY little effect. Drug lords are made possible through this war. In a capitalist society, Pot would be dirt cheap, taking the profit out of it, and would reduce violence, reduce peer pressure on drugs, and not drive the occasional joint smoker out of house and home. You can find more on that as well on Harry's site, as well as lp.org