Virginia voters head to the polls Tuesday to decide a closely watched redistricting referendum that could reshape the state’s congressional map and carry national implications, with both parties bracing for a tight result that could hinge on turnout in a low-profile spring election.

The proposal would allow the General Assembly to temporarily redraw congressional districts, a move Democrats argue is needed to counter Republican-led redistricting efforts in other states. If enacted, the plan could shift Virginia’s current 6-5 Democratic House majority into a map that favors Democrats in as many as 10 of the state’s 11 districts.