Senate election results are announced by individual states, with states on the eastern coast typically being announced first and western states being announced later. One-third of the Senate is up for grabs every two years, with the winners serving a six-year term.
Winners are typically announce over the airwaves, but the two main organizations who actually make the official call in a given state are Reuters and The Associated Press.
Senate Election Results
Current Senate voting results are updated live by both the Associated Press and Reuters. They partner with local election experts to accurately track and predict who will win a given election.
The winner of the most votes is the winner of the election in the vast majority of states, with the exception of Georgia and Louisiana, which hold runoff elections if no candidate received fifty percent of the vote in the general election.
Many states are not competitive in most election cycles, with the Democratic or Republican Party firmly being in control of a seat regardless of who the candidate is. Of the over thirty seats up for grabs each election cycle, ten to fifteen are usually a tossup with the remaining elections being firmly in either sides camp.
Whether or not a state allows early and/or absentee (mail) voting will greatly impact when a given race will be called. States that allow early and absentee votes to be counted before election day will typically be able to declare a winner on election night, but states that don't begin counting early and absentee votes until election day may take extra time to count all the votes before being able to accurately declare a winner.
Quality Real Time Senate Election Results Publications:
The Associated Press
Reuters
FiveThirtyEight
CNN
ABC/NBC/CBS
New York Times
Washington Post
Early, Absentee, and Mail-in Voting
Thirty-eight states and Washington, D.C. have some form of early voting and five states vote exclusively by mail.
States have wide latitude when it comes to early voting. Many states allow their citizens to vote early for any reason while others require a valid excuse in order to vote early or by mail. Additionally, some states allow early, in-person voting for weeks before an election while others have a limited number of days they allow early in-person voting to take place.
Ballots cast early at an official polling site are counted immediately while ballots cast by mail are opened and added to the official total according to state law. States that wait until election day to begin opening ballots cast early may take longer to report the results compared to states that begin counting ballots as soon as they are received by state election officials.
Declaring Senate Election Winners
A winner is declared in a state when it is clear a candidate has or will have more votes than any other candidate in the state in every state other than Georgia and Louisiana, who require a candidate to win fifty percent of the vote before they will be declared the winner. Typically the winner of a state will be called by The Associated Press and/or Reuters and then relayed to the American people by media outlets.
If a state is too close to call then most states give the losing candidate an opportunity to request a partial or full recount. The candidate requesting the recount is typically required to submit a deposit toward the cost of conducting the recount, which is then refunded if the recount reverses the result of the election. If a recount does not change the results then the candidate who asked for the recount is required to pay most, if not all, of the costs associated with the recount.
Other states have automatic recounts when the election result between the top two candidates is within a certain percentage. In these cases, the state covers all costs associated with the recount.
In the vast majority of elections, Senate races are won by enough votes that a recount is not necessary.