Though Democratic turnout for early voting has soared this year compared with last time, no Democrat has won a statewide race in Texas since 1994, making the primaries all-important.

The last stand of Bush’s political career could be the Alamo. His predecessor and main rival, Jerry Patterson – a history buff who used to carry guns in his cowboy boots and cultivated a relationship with the pop star and leading Alamo artefact collector, Phil Collins –has made Bush’s supposed failure as a steward of the historical battlefield site into a key campaign issue. Bush has also drawn criticism for the slow pace of disaster recovery efforts following Hurricane Harvey.

A Bush spokesman did not respond to a request for comment on the campaign.

“The guy is cloistered,” Patterson said of Bush in the Houston Chronicle. “He’s kind of like Kim Jong-un – he doesn’t get out much unless it’s in a real secure environment.”