Former President George. W. Bush has so far remained mum about the 2024 election, even as his vice president endorsed Vice President Kamala Harris. Bush’s silence became the topic of discussion on CNN’s “NewsNight” on Tuesday night, with a Democratic strategist calling the Republican’s refusal to endorse “upsetting.” Anchor Abby Phillip played two clips of Bush in which he asked Americans to be “citizens, not spectators,” and to participate in the country’s “active public square.” “My hope is you will speak out on issues that matter to you,” Bush said in a 2015 clip. “By taking part in America…