If anything, their marriage could show the beauty in America's multiculturalism. It perfectly embodies California, and perhaps she could have a stronger connection with White voters than Obama (but not as much as the overly nationalistic Trump).
What was wrong with Obama's connection with white voters? I don't think he was to blame for his 39% showing among whites in 2012... and at least he was able to hold the Rust Belt voters who flipped to Trump in 2016. His whole party lost white voters badly that year (and even worse in both subsequent election years), not just him.
