Democrats are about to find out how worried they need to be about Black voter support.

After a lot of hand-wringing in recent years, elections next month in Mississippi and Virginia — two Southern states with large Black populations — will offer one final, robust read going into 2024 on the extent of the slippage among Democrats’ most reliable bloc of voters.

The warning signs have been flashing.

President Joe Biden’s approval rating with Black voters has dropped disproportionately compared with white voters, polls show, driving down his overall numbers. Last week’s election of a Republican governor in Louisiana, the first in eight years, suggested diminished voter enthusiasm in the areas with the largest Black populations.