He also says Obama is offering a vision for "trickle-down government" and that Americans saw "two very different visions for America" during the first presidential debate Wednesday night in Denver.
The Republican nominee spoke Thursday morning during a surprise appearance at the Colorado Conservative Political Action Committee's meeting in Denver.
A smiling Romney took the stage to sustained cheers from the audience of conservative activists.
Romney was introduced by four of his five sons. His appearance at the meeting came before a scheduled flight to Virginia, where he and running mate Paul Ryan were to address an evening rally.
(Copyright 2012 by The Associated Press. All Rights Reserved.)