My colleague David Wasserman recently looked at key House races where "spoiler" candidates could make a difference in close congressional contests. There are a few races for Senate and governor worth watching on Election Night as well where a third-party candidate could have particular influence.

With the closest Senate races in both our Toss Up and even into some Leans ratings within the margin of error, any other non-major party candidate could play spoiler, even if it's by one point or less. That holds true for Senate races in Pennsylvania, Nevada, and perhaps New Hampshire or North Carolina. In Nevada, several minor party candidates are on the ballot, but the state always includes the ballot option of "None of These Candidates," which is often the largest spoiler. It has been decisive before. As the Nevada Online Encyclopedia notes, in the 1998 Senate race, Democratic Sen. Harry Reid beat then-Rep. John Ensign by just 428 votes; 24,470 voted for "None."

Then there are races where third-party candidates have had an outsized influence in the past but may not this time.

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