Unfortunately, the GOP has increasingly embraced conspiratorial thinking, and that includes vaccine skepticism and hesitation.
Trump knew since May 2020 that Fauci was lying - he had the DOE LLNL investigate the lab leak theory, and LLNL reported that COVID-19 was possibly from a lab. So yeah, he doesn't believe experts who can't stop lying.
https://wjla.com/news/nation-world/exclusive-classified-stud...
> he's been kind of lukewarm on promoting the vaccines compared to Democrat leaders
Trump's Warpspeed (Spring 2020) funded the vaccines. I haven't heard him say any negative things about them.
https://en.wikipedia.org/wiki/Operation_Warp_Speed
Republicans/Trumpists believe in personal choice, so I wouldn't expect him to be a cheerleader for getting a shot.
> the GOP has increasingly embraced conspiratorial thinking,
After Fauci lying for over a year, 2 failed impeachments, being deplatformed on social media, being told they have no standing to dispute elections, being told CRT doesn't exist - half of the country knows what a Marxist conspiracy feels like first-hand, and they're pissed.
Most of the major stories about Trump since 2019 on CNN, MSNBC and WaPo have been retracted in 2021 (after the election). I suggest you stop reading those sources and spend a couple months reading Fox and NTD - I can't think of anything they're retracted.
Do a Youtube search for "cpac trump full speech 2021" - the only full version is on Sky Australia's channel - for now. All the copies on US channels have been blocked or prevented.