Republicans didn't steal patriotism. Some Democrats just started believing that loving one's country meant trashing it. Being proud of the United States is certainly not a prerequisite in their mind. To the contrary, it is downright unpatriotic to love one's country unconditionally. The definition they most often cite is the Marxist Paul Robeson's: "The patriot is the person who is never satisfied with his country." Anyone who walks across a college campus will see evidence of this somewhat Orwellian thought-process on a popular t-shirt that reads, "Dissent is patriotic." (Of course dissent should be tolerated, and sometimes it is admirable--but is it necessarily patriotic?) This sentiment was also very much reflected in Obama's decision to stop wearing the American flag lapel pin. Recall what he said:
"You know, the truth is that right after 9/11, I had a pin," Obama said. "Shortly after 9/11, particularly because as we're talking about the Iraq War, that became a substitute for I think true patriotism, which is speaking out on issues that are of importance to our national security, I decided I won't wear that pin on my chest."
Of course, what Obama really meant when he said "speaking out on issues" is opposing the administration.