They are indeed against unconstitutional wars.
"We condemn the presidential assumption of authority to deploy American troops into combat without a declaration of war by Congress, pursuant to Article I, Section 8 of the U.S. Constitution."
However, I see things differently than you probably do.
Bush had congressional approval to use force on Iraq. Something Ron Paul and the Liberatarians refused to recognize, because although congress approved the use of force they didn't use the magic words "Declare War On".
Obama did not have congressional approval to use force on Libya, because the only standing authority was to use force in the event of an imminent threat to the U.S. and Libya wasn't in any way an imminent threat.
Thanks for the reply. But really there is no excuse for not using the ‘magic words’. UN resolutions does not cut it for me nor does a Constitutional work-around of ‘serious consequences’. Unite the nation ask congress for a formal declaration of war. Why not?