“Chasing the Hill” follows the reelection campaign of a Democratic representative from California struggling to fend off a primary challenger. She hires a veteran political consultant at the last hour in a desperate effort to hold on to her seat. Robin Weigert, who earned an Emmy nomination for her role in HBO’s “Deadwood,” plays Rep. Kristina Ryan. The 42-year-old actor, who grew up in D.C. and attended Sidwell Friends — where President Barack Obama’s daughters are enrolled — says there couldn’t be a better time to play a character treading water in a tough reelection race.