As the Democratic presidential nominee, she would give Democrats their best chance at retaining the White House.
As it stands, President Biden's chances of winning reelection against a credible Republican presidential candidate (which excludes former President Trump) aren’t great. If Michelle were on the Democratic ticket, Barack would be a close adviser, not just to Michelle but to the administration and the Democratic Party. In short, capturing Michelle would be the best way to recapture what Democrats see as that ole’ Obama magic. And she would become the first women President of the USA.
