President Trump argued in his post-election news conference that the Republican Party’s performance in the midterms defied history. An analysis by a JPMorgan economist suggests Trump is right — just not in the way he intends. 

Measured against the strength of the economy, the GOP’s losses in the House mark the worst midterm results for a president's own party in at least a century, per Michael Cembalest, JPMorgan Asset Management’s chairman of market and investment strategy.