Donald Trump's job approval is upside-down (38% approval to 57% disapproval). It's been that way for quite a while now, and it's not improving. But that doesn't mean he doesn't have his core areas of support. Evangelical hubs support him by 20 points, working class areas support him by 13 points, rural areas support him by 5 points, and LDS areas support him by 4 points.
But those areas don't make up a majority of Americans -- far from it. Those areas (1,349 counties) have about 35 million voters. That may sound like a lot of voters, until you consider that the 47 biggest urban counties have about 59 million voters -- an advantage of 24 million voters (and these urban counties disapprove of Trump by 43 points).
Another matter that should concern Trump (and Republicans) is that he has lost the support of four groups -- seniors, military posts, suburbs of middle-sized cities, and exurbs. The counties where these groups rule supported Trump at his 100 days in office -- but no longer do. He has dropped by 12 points among seniors, 13 points on military posts, 9 points in middle suburbs, and 14 points in exurbs.
These charts are from the Gallup Poll -- done by daily surveys in the month of June of a random national sample of 15,252 adults, with a 1 point margin of error.