Stabenow's campaign said it's giving up on arranging debates because Hoekstra refuses to accept an arrangement that has been used in all of Michigan's Senate races since 1996.
The plan was for two debates broadcast on public television — one before the Detroit Economic Club and the other at Grand Valley State University.
Hoekstra wanted as many as six debates that would be shown over network television.
His campaign said Hoekstra was willing to participate in both of the traditional debates, plus others, but Stabenow refused to set terms. Hoekstra said Stabenow was afraid to defend her record, while Stabenow's spokesman said Hoekstra was interested only in making political attacks.