Just a couple of problems I have with Ron Paul are these votes he's made and positions he's taken:
Voted NO on deterring foreign arms transfers to China (Jul 2005)
Voted NO on expanding research to more embryonic stem cell lines. (Jan 2007)
Voted NO on allowing human embryonic stem cell research. (May 2005)
Voted NO on restricting interstate transport of minors to get abortions. (Apr 2005)
Voted YES on banning gay adoptions in DC. (Jul 1999)
Opposes the death penalty. (Jan 2007)
Voted NO on subjecting federal employees to random drug tests. (Sep 1998)
Voted NO on requiring states to test students. (May 2001)
Abolish the federal Department of Education. (Dec 2000)
Supports a Constitutional Amendment for school prayer. (May 1997)
Voted NO on establishing nationwide AMBER alert system for missing kids. (Apr 2003)
Voted NO on reforming the UN by restricting US funding. (Jun 2005)
Close departments of Energy, Education & Homeland Security. (May 2007)
Voted NO on prohibiting lawsuits about obesity against food providers. (Oct 2005)
Voted NO on prohibiting product misuse lawsuits on gun manufacturers. (Oct 2005)
Voted NO on prohibiting suing gunmakers & sellers for gun misuse. (Apr 2003)
DHS is unmanageable bureaucracy--eliminate it. (May 2007)
Voted NO on federalizing rules for driver licenses to hinder terrorists. (Feb 2005)
End draft registration; all-volunteer forces . (Dec 2000)
Immediately work to phase out the IRS. (May 2007)
Trusts the Internet a lot more than the mainstream media. (May 2007)
There are more, of course, but that's a fair start.
Here's the source:
Ron Paul On The Issues