Alec Baldwin, 46, has long been a Democratic Party supporter. Younger brother Stephen is new to the political scene.
The 38-year-old actor, a born-again Christian, says his support for the Republican Party is less about politics and more about religion.
"My desire to be at the RNC was this goal that I have to support the candidate that I believe has the most faith," Stephen told "Access Hollywood" in an interview Tuesday. "Systematically, God is being erased and removed from our culture, our society, our government."
He added, "I think it's kind of freaky, man."
The Republicans have been holding their convention this week in New York. During the gathering, the party officially chooses President George W. Bush as its candidate for the Nov. 2 election.
Alec, who was at the Democratic convention in Boston in July, told the syndicated entertainment TV show that he has concerns about Stephen being in a political spotlight.
"Stephen's been fairly apolitical for a long, long time. Then he embraced a born-again Christian faith, which is very near and dear to him and very real for him. As a result of that, of course, certain operatives of the Republican Party came to him and said, `Why don't you come on over and join our unit of spokespeople who are show business?'"
Alec, who starred in the 2003 film "The Cooler," said he told Stephen: "When they are done with you, they are going to throw you in the wastebasket" and cautioned him about carefully choosing his words "when ... they stick a microphone in your face."
Will Stephen listen? Alec doesn't expect it.
"Of course, he's going to ignore my advice as he's done throughout his life," the elder Baldwin brother said.