As a large, unruly audience jammed Jordan Hall to jeer and laugh, Robert Welch, the founder of the John Birch Society, last night defended his organization against "ludicrous, ridiculous, and rotten" charges of "secrecy and bigotry."

Welch claimed that many organizations besides the Birchers "refuse to publish their membership lists," and declared that "the left wing and liberal press was not aware of the Society" for 18 months after its founding because these papers have a "sloppy and distorted view of the American scene."

"We lean over backwards to avoid discrimination," Welch said. He decried charges that Birchers practice religious and racial bigotry as "the most rotten of all smears."

Welch defended former Gen. Edwin D. Walker, a professed Birchite, as a "patriotic, good-intentioned American" who is "innocent of any illegal action" at the University of Mississippi.

"Walker fell into a left-wing trap in Mississippi," Welch declared," and false and vicious press reporting distorted the incident."

With considerable feeling, Welch repeated a charge that Supreme Court Chief Justice Earl Warren "is attempting to break down our Constitution." Welch again called Warren an agent of the Communist conspiracy and declared that he "should be impeached." The audience hissed and jeered.

Welch declared the membership goal of the Society to be "one million fervid patriots and loyal citizens," and said that the Birchers continue to grow, despite vicious attacks.

"If we can grow until we have as many members as the comsymps, we can rout the communist conspiracy," Welch declared. "But the Communists have beguiled many good Americans into attacking the Birch Society," he warned.

The one time candy manufacturer coined a word at the Ford Hall Forum: "Americanist," which he called the antithesis of Communist." He said Birchers will "defeat the Communist conspiracy by disseminating Americanist literature, forming Americanist fronts, and sponsoring Americanist speakers."