**EMBARGO: No electronic distribution, Web posting or street sales before Friday 3:01 a.m. ET July 05, 2019. No exceptions for any reasons. EMBARGO set by source.** A map of Texas House district No. 108 hangs on the door at the campaign offices of Tom Ervin, who is one of three Democrats campaigning for a Dallas-based State House district that is up for election in 2020, in Dallas, July 2, 2019. With the nation?•s political maps hanging in the balance, Democrats are racing to win back statehouse chambers and Republicans are rushing to defend gains from 2010. (Allison V. Smith/The New York Times)