Everyone expects President Trump to use his record-breaking campaign war chest to launch vigorous attacks on his November opponent, Joe Biden, but the President’s recent verbal assaults on Barack Obama do nothing to enhance his re-election prospects.

2016 exit polls showed 16% of white, working-class supporters who gave Trump his key swing state victories previously backed Obama. Insulting a president they once supported as “incompetent” and “criminal” won’t cement their connection to the current incumbent. Diminished black turnout also helped Trump in 2016—with only 60% of eligible black voters showing up for Hillary, compared to 66% who turned out for Obama in 2012.

Making the ex-president the focus of new attacks, rather than Biden, could easily mobilize another African-American tidal wave in turnout, while alienating masses of blue collar, white voters who switched last time from Obama to Trump. It’s a formula for damaging Republican chances, not for winning re-election.