DETROIT — Instead of capitalizing on Republican vulnerabilities to retake the Senate on Tuesday, some of the Democratic Party’s most prominent figures and their allies are consumed by a fight of their own making.

In Michigan, where Democratic Senate nominee Abdul el Sayed is locked in a closely watched contest against Republican Mike Rogers, a bitter and messy primary feud has resurfaced just days before voters head to the polls. Former rival Rep. Haley Stevens (D-MI), who lost to el Sayed in August, has continued challenging his positions on Israel, while his campaign has asked her to stay away from his remaining events.