Michigan Governor Gretchen Whitmer has endorsed Representative Haley Stevens in Michigan’s Democratic primary for the US Senate. The backing could strengthen Stevens’ campaign ahead of early voting, particularly because Whitmer has won statewide elections by large margins.

Stevens is described as the more centrist candidate, while progressive doctor Abdul El-Sayed is also considered a front-runner. Early voting was due to begin on Saturday, making Whitmer’s intervention a potentially significant development in a closely watched primary.