Based on one bad year? Coming into this cycle, Gallup had a pretty good track record in statewide polling, based on the comparison data on SurveyUSA's website. They were in the top quartile in terms of accuracy before this year.
I suppose. They do gold-standard national polls. I'm surprised that they flounder a bit with state polls. Rasmussen straightened up within 4 years so I guess they can to.