How 2 competitive districts in Georgia became a very red one and a very blue one

A man looks at newly drawn congressional districts for Gwinnett County, Ga., at a meeting of county Democrats this month.

Sam Gringlas / Sam Gringlas

The sign-in table at May’s meeting of the Gwinnett County Democrats is covered in literature.

There are sheets listing early voting locations, stacks of glossy campaign flyers and colorful maps of the new congressional districts in suburban Atlanta.

These new maps have Democrats like Catherine Valyi facing a difficult choice.