Robert Kraft’s son, Josh Kraft, has left the Patriots franchise as he zeroes in on the Boston mayoral race, where early polling shows he’s trailing substantially to incumbent Michelle Wu. Josh, 58, is trailing Wu in the polls, 59-29 percent, ahead of this November’s election cycle. They are running as Democrats.

The poll of 500 Boston voters likely to participate in the Sept. 9 preliminary election showed a wide gulf between Wu and Kraft, who drew 30 percent support to her 60 percent.

Boston Mayor Michelle Wu is leading Josh Kraft by 30 points with about a month to go before the first ballots are cast in the city's preliminary election. The post Wu has comfortable lead over Kraft,