The godfather of the conservative movement, William F. Buckley Jr., caused a stir at Yale University on Wednesday evening by announcing that he was delivering his final political speech.

The founder of the conservative magazine National Review, a novelist, and a former co-host of the Public Broadcast Association’s longest-running television series “Firing Line,” Mr. Buckley delivered his speech to the Yale Political Union, a debating society of which he was a member as an undergraduate.

But Mr. Buckley, who has made a habit of delivering “last speeches” since he officially retired from public speaking in 2000, was the first to make light of the situation.”Every now and then, I flub,” Mr. Buckley said. “So I just got a little theater out of saying it was my last speech.”

“I think this was his fifth final speech,” Mr. Buckley’s nephew, L. Brent Bozell III, said. “He’s given more final speeches than Barbra Streisand has given final concerts.”

Mr. Bozell said Mr. Buckley doesn’t know how to decline an invitation.

The Yale Daily News reported that Mr. Buckley “surprised” the 500 members of the audience with his announcement that his remarks marked “my terminal speech on public affairs.”

“I am very honored to have been a part of William F. Buckley’s last public appearance,” the president of the Yale Political Union, Roger Low, said.

Mr. Buckley took the opportunity to devise the topic of his speech: why the Democratic candidates for the upcoming elections should withdraw. “I took the liberty of writing my own resolution, but I wrote a preposterous one,” he said.

Nonetheless, Mr. Buckley, 80, argued in his speech that “Democrats are dominated by craven, greedy, hypocritical thought” and criticized them for not demanding the immediate withdrawal of American troops from Iraq.

He reminded the union of its tradition of “carrying out the speaker on your shoulders when positively transported by enthusiasm for the resolution, for the speaker, and for the speaker’s advocacy,” but asked it to “rein in that impulse.”