By Bob Brigham Donald Trump’s grip on the Republican Party is being increasing challenged by GOP rivals who have less fear of the former president’s rage following Georgia’s primary election results. Former Gov. Chris Christie has emerged as a leading critic of Trump’s fixation on his delusions about the 2020 presidential election, which was won by Joe Biden. “We have to be the party of tomorrow, not the party of yesterday,” Christie told Politico. “But more important than that, what we have to decide is: do we want to be the party of me or the party of us? What Donald Trump has advocated is f…