DETROIT (AP) – Hillary Clinton and Bernie Sanders are putting the global economy at the center of their pitch to Democrats, trading charges about who would best represent American workers as their presidential campaign shifts to a series of Rust Belt primaries.

Clinton planned to deliver a policy address Friday in Detroit outlining ways to remove economic barriers for families, giving her the opportunity to respond to Sanders, who has accused her of supporting trade deals that have had “disastrous” consequences for workers.

The Democrats’ focus on manufacturing jobs and trade policy will form the backdrop for Michigan’s primary on March 8 and contests a week later in Ohio, Illinois and Missouri.