How midterm elections could shift balance of power in state legislatures

With all eyes on marquee races for Congress and governorships, Democratic and Republican groups have poured millions of dollars into under-the-radar battles for the control of state legislatures.

The stakes this year are unusually high. A Supreme Court decision in June handed the question of abortion to state legislatures for the first time in decades, fallout from the 2020 election has pushed many states to reconsider their voting laws, and fights over whether racial and gender-based material belongs in school are being waged in a growing number of states.

Republicans are fighting to defend vulnerable...