Arizona Democrats maintained small but dwindling leads over their Republican rivals for U.S. Senate and governor.
The races remained too early to call two days after the election, with some 600,000 ballots left to count, about a quarter of the total cast.
Protracted vote counts have for years been a staple of elections in Arizona, where the overwhelming majority of votes are cast by mail and many people wait until the last minute to return them.
Democrats opened big leads early on election night, when only mail ballots returned early were reported, but they saw their margins dwindle as more Republican ballots were counted.
On Thursday, Democrats led in the races of Senate, governor, secretary of state and attorney general.