What Is a Runoff?
Not every primary ends on election night. Some races send their top finishers to a second round of voting before anyone becomes the nominee — here's what that means and how it shows up on this site.
The second round, in plain English
In most primaries, the candidate with the most votes wins the nomination, full stop. But some states require the winner to clear a vote threshold — typically a majority — to claim the nomination outright. When a crowded field splits the vote and nobody reaches it, the top finishers (usually the top two) meet again on a later date. That second election is the runoff, and only its winner becomes the nominee. A primary can even produce runoffs on both parties' sides at once, each with its own pair of candidates.
How a runoff looks on Decision Labs
A race headed to a runoff is labeled “Runoff pending” — not “called,” because nothing has been decided yet. The race page shows which candidates advanced, the scheduled runoff date, and the sources that reported the first-round result; the primaries page lists every race currently in a runoff. Once the runoff is held, the result goes through the same review as any other: we show a race as decided only when at least two independent, authoritative sources agree.
Top-two (“jungle”) primaries are different
In a top-two primary — often called a “jungle” primary — all candidates from every party appear on a single ballot, and the top two finishers advance to the general election. There's no party nomination to win, so the “second round” is the general election itself. Race pages note when a race uses this system.
A caution about pre-runoff polling
Polls taken before the first round measured a different contest — a larger field, different matchups. When a race moves to a runoff, treat earlier primary polling as history, not as a read on the two-candidate race. Our race pages flag when the polling shown predates a result; for the general problem of comparing polls, see Why Polls Disagree.
One honest limitation
Runoff thresholds, dates, and which offices use them vary by state and can change by legislation. We don't maintain a 50-state table of those rules; we describe each race's system on its own page, sourced the same way as everything else. Our sourcing bar is documented in the editorial standards.