Senator Mark Kelly, a Democrat, holds an edge in his bid for re-election, but the race for governor appears to be a true tossup, even as several Republican candidates sow doubts about the results.
In Arizona and Nevada, Republicans’ path to victory appeared to narrow, though both races remain close. The G.O.P.’s odds of success are greater in the House.
The contests are close in Arizona, Georgia, Nevada and Pennsylvania. Many voters want Republicans to flip the Senate, but prefer the Democrat in their state.