Uh, they did initially. That's why Paul never placed higher than 10% in the primaries.
All this talk about Paul getting hordes of liberals crossing over to support him didn't materialize. What's going to happen though, is that Paul supporters, who are mainly new voters and libertarians frustrated with the GOP, aren't going to vote for McCain, which guarantees a Clinton victory.
And I don't want to hear any non-sense about Paul supporters being "traitors," after FReepers and conservatives voted for Hillary in the primaries per Operation Chaos.