Bush is just trying to protect US pharmaceutical industry profits. This is an issue that individual states want the right to decide.
"Minnesota's governor establishes the first state-sanctioned system for prescription-drug reimportation..."
http://pn.psychiatryonline.org/cgi/content/full/39/18/6
"The governor of Illinois Thursday backed a lawsuit against the U.S. Food and Drug Administration to overturn the ban on buying prescription drugs from Canada."
http://www.pbs.org/newshour/updates/..._02-26-04.html
I don't see the Democrats allowing Bush to have his way.