WASHINGTON — Rep. Adam Gray was one of only six House Democrats — and the only one from California — who voted with Republicans in favor of a deal to end the government shutdown, and there was a calculated reason behind that decision.Gray, a first-term Democrat from the Central Valley, is running for reelection in a majority Latino district that national Republicans are expected to heavily target as they defend their narrow House majority in next fall’s midterm elections. Last year, Gray won his seat by 187 votes, and although redistricting has since made the 13th District more favorable to...