Among those who will be speaking to the Republicans are at least two possible 2012 presidential candidates, Mississippi Gov. Haley Barbour and former Speaker of the House Newt Gingrich. Also attending will be Texas Gov. Rick Perry, who has raised his national profile enough lately to generate speculation that he, too, is considering a White House run.Other guests include Virginia Gov. Bob McDonnell, former Sen. Phil Gramm; former U.S. Secretary of Health and Human Services Michael Leavitt, columnist George Will and radio host Dennis Prager.