Hickenlooper defied a subpoena from the state's independent ethics commission over Republican charges that he violated the ethics law by taking private flights and car trips as governor.
The commission found Hickenlooper had violated the law in one flight and one limousine trip at the secretive Biltsberger meetings in Rome.
The combination of the gaffes and setbacks was enough to lure Republicans to launch millions of dollars in ads attacking Hickenlooper.
Colorado's Democratic establishment, from Gov.
Republicans hope that Hickenlooper has been banged up enough to give Gardner a chance in the November election.