On an otherwise banner night, Georgia Republicans had one cause for alarm: Cobb County turned blue.

Georgia Republicans have long fretted about Gwinnett County's Democratic drift. Cobb was thought to be safe for longer, because the same demographic trends are happening more slowly there. Instead, both bastions of conservatism flipped . The GOP must address this abrupt change to keep Georgia red.

Let's start with a caveat: There are reasons to suspect Cobb's turn toward Hillary Clinton was chiefly about the shortcomings of Donald Trump, especially as seen by suburban white women. Most other Republicans on Cobb ballots won, including hometown U.S. Sen. Johnny Isakson.

But Clinton's competitiveness there is also a result of a somewhat stronger Democratic effort in Georgia. Arguably, that's part of the reason she lost the White House: Her bid to expand the map diverted some resources from the "blue wall" states she wound up losing. Not a ton of resources, but then again as I write, it appears she lost Michigan , Pennsylvania and Wisconsin by fewer than 110,000 votes combined.

Maybe a future Democrat decides the Clinton campaign made a mistake, and re-focuses on the Midwest. Maybe not.

Trump's margin was smaller here than in purple Ohio . Florida , Georgia and North Carolina were all relatively close, and together they offer 14 more electoral votes than Trump's Midwestern trio. Heck, they would almost make up for losing Ohio, too. As the electorate changes and Republicans embrace populism, it's conceivable Democrats will try to win in the Sun Belt, not the Rust Belt.

The populist part is particularly pertinent. It's no secret Trump broke through the blue wall by courting working-class whites who have watched technology and, to a lesser extent, trade take away their jobs. But guess where else their jobs have gone ? Here.

Cobb and Gwinnett aren’t the only places in Georgia where Clinton did better than Barack Obama did four years ago. By my count, there are 17 such counties. They’re not just among the state’s most populous. They’re also among its most prosperous: 14 of them ranked among the state’s top 25 for median household income.

While Georgians like our populism as much as the next state, we aren’t the losers from global trade. We still make things and grow things, but we ship and truck and fly even more things. If the GOP under Trump turns away from the policies that helped spark our relatively rapid growth, that might turn off Georgians — especially in Atlanta’s relatively wealthy suburbs.

What happens nationally isn’t within the Georgia GOP’s control. Here’s what is: Addressing metro Atlanta’s problems.

Traffic comes to mind, and legislators are not just funding more road construction but edging ever closer to transit. Education is another big one. The Opportunity School District failed, but metro Atlanta still has dozens of chronically failing schools. What’s Plan B? (I have some ideas, but that’s another column.)

Of course, the “other Georgia” faces challenges, too: stagnant economic growth, struggling hospitals and, in some parts, equally bad schools. To keep Georgia red, Republicans will need to address both sets of problems. Soon.