Doonesbury by Garry Trudeau for February 20, 1971
Transcript:
President Nixon (on TV): My fellow Americans! Many of you have asked me what I am doing...about the cost of living, rising crime, and the war!! Before I answer you however, I want you to meet someone...perhaps some of you remember this little feller...Say hello to America, Checkers! Checkers: Woof! Woof! Woof!
Checkers was actually dead by this time…