California — Former White House adviser Steve Bannon on Friday depicted former President George W Bush as bumbling and inept, faulting him for presiding over a "destructive" presidency during his time in the White House.Bannon's scathing remarks amounted to a retort to a Bush speech in New York earlier this week, in which the 43rd president denounced bigotry in Trump-era American politics and warned that the rise of "nativism", isolationism and conspiracy theories have clouded the nation's true identity.But Bannon, speaking to a capacity crowd at a California Republican Party convention, said Bush had embarrassed himself and didn't know what he was talking about.Bannon said Bush has no idea whether "he is coming or going, just like it was when he was president"."There has not been a more destructive presidency than George Bush's," Bannon added, as boos could be heard in the crowd at the mention of Bush's name.The remarks came during a speech thick with attacks on the Washington status quo, echoing his call for an "open revolt" against establishment Republicans. He called the "permanent political class" one of the great dangers faced by the country.A small group of protesters gathered outside the hotel where Bannon spoke, chanting and waving signs — one displaying a Nazi swastika. The protesters were kept behind steel barricades on a plaza across an entrance road at the hotel, largely out of view of people entering for the event. No arrests were reported.Bannon also took aim at the Silicon Valley and its "lords of technology", predicting that tech leaders and progressives in the state would try to secede from the union in 10 to 15 years. He called the threat to break up the nation a "living problem".He also tried to cheer long-suffering California Republicans, in a state that Trump lost by over 4 million votes and where Republicans have become largely irrelevant in state politics. In Orange County, where the convention was held, several Republican House members are trying to hold onto their seats in districts carried by Hillary Clinton in the 2016 presidential contest."You've got everything you need to win," he told them.He ended his speech with a standing ovation.Bannon is promoting a field of primary challengers to take on incumbent Republicans in Congress. But in California, the GOP has been fading for years.The state has become a kind of Republican mausoleum: GOP supporters can relive the glory days by visiting the stately presidential libraries of Ronald Reagan and Richard Nixon, but today Democrats control every statewide office and rule both chambers of the Legislature by commanding margins.Not all Republicans were glad to see Bannon. In a series of tweets last week, former state Assembly Republican leader Chad Mayes said he was shocked by the decision to have the conservative firebrand headline the event."It's a huge step backward and demonstrates that the party remains tone deaf," Mayes tweeted.California Republicans have bickered for years over what direction to turn — toward the political center or to the right.Bannon also argued that the coalition that sent Trump to the White House, including conservatives, Libertarians, populists, economic nationalists, evangelicals, could hold power for decades if they stay unified."If you have the wisdom, the strength, the tenacity, to hold that coalition together, we will govern for 50 to 75 years," he said.Most of the state's governors in the 20th century were Republicans, and state voters helped elevate a string of GOP presidential candidates to the White House. But the party's fortunes started to erode in the late 1990s after a series of measures targeting immigrants, which alienated growing segments of the state's population.In 2007, then-Gov. Arnold Schwarzenegger warned party members that the GOP was "dying at the box office" and needed to move to the political center and embrace issues like climate change to appeal to a broader range of voters. In 2011, a state Republican Party committee blocked an attempt by moderates to push the state GOP platform toward the center on immigration, abortion, guns and gay rights.The decline continued. Republicans are now a minor party in many California congressional districts, outnumbered by Democrats and independents. Statewide, Democrats count 3.7 million more voters than the GOP.Political scientist Jack Pitney, who teaches at Claremont McKenna College, said he doubted the speech would color the 2018 congressional contests, which remain far off for most voters.More broadly, he said Bannon's politics would hurt the GOP, including among affluent, well-educated voters who play an important part in county elections."Inviting him was a moral and political blunder," Pitney said in an email.