Trump came along when fear and anxiety were high among large % of white people. They are programmed/conditioned/socialized to believe that the world centers around them, and that they (white men) are the natural leaders.
Obama got elected twice, they saw the projection for 2043 with them no longer being the majority population, and they went into panic mode.
Trump exploited those fears
This basically. Combine that with the fact that social media exploded during that time and the nut job conspiracy theorists could now spew their rhetoric to a mass amount of people as well as algorithms to feed people propaganda.
Can’t forget too that homosexuality/LGBTQ became front and center and the “liberal agenda” during that time as well. Cancel culture, me too, BLM, defund the police, etc,. This all created a perfect storm for someone like Trump and his cronies.
Remember Sarah Palin and the tea party bullshyt leading up to 2008. That was a foreshadowing of what was to come. Nobody including establishment Republicans took that seriously. That along with white grievance birthed MAGA.
I will say that it was Obama’s second term in 2012 that really turned the country into what it is today. 2008-2012 the country loved that man and in fact a lot of white people voted for him especially after Bush Jr’s bullshyt run. Something happened in 2012 where Democrats started focusing on fringe polarizing issues (Trans, gay rights, BLM, abortion, culture wars). It exposed the quiet bigotry that’s always been present in this country and Republicans, more specifically MAGA capitalized on it with the whole “make America great again” narrative where it positioned America as “loosing its way” aka THEY (anyone not white spearheaded by Obama) are taking over.