The first polls closed at 6 p.m., but some key results are not expected for several hours or days.
Elsewhere, Republicans are also looking to regain the governorsโ mansions in Kansas, Maine, Michigan, Minnesota, Nevada, New Mexico, Oregon and Wisconsin. In addition, 36 gubernatorial elections are being held across the US, including an unexpectedly close contest in New York between Democrat Kathy Hochul and GOP Rep. Recent polls also indicate surprisingly close races in Democrat-held New Hampshire, while Republicans will need to hold open seats in North Carolina and Ohio to consider the night a success.