Defending the constitution is a platform generally associated with the republican party, not the democrats. Strict constitutionalists are who republicans like to see as judical appointees, not democrats. Reducing the scope and power of the federal government is a traditional republican value, not a democrat one. Paul absolutely belongs on the republican stage, or at least a conservative stage, for those reasons alone. That liberals might benefit from or be attracted to the consequences of these principles does not make Paul a spokesman for them. He is a spokesmand for conservatives who understand conservatism.
The democrats like having Ron Paul on stage since he appeals to the republicans disgruntled by mainstream republicans. The democrats hope this appeal will pay dividends when a number of republicans decide to vote third party or stay home.
So it's an entitlement? Can't he do all of those things from the Libertarian stage?
Why does he run as a Republican when he is a Libertarian? Why can't he show honesty in this most basic area?