A governing trifecta means that a party holds the presidency and both chambers of Congress. Each of these options are conditional markets asking, if the listed party wins all of the chambers/office listed, will they achieve a governing trifecta in the 2024 elections? For example, "Democratic; House and Presidency", means "Conditional on Democrats winning the House majority and a Democrat being elected president in 2024, will Democrats win a governing trifecta?" (in other words, will they also win the Senate?).

Winning the presidency means that the party's nominee wins the Electoral College vote or is elected by the House if there is no Electoral College winner. Winning a chamber of Congress means that the party wins a majority of seats in that chamber. A mere plurality does not count as a majority. For the Senate, 50 seats plus the vice president's tiebreaking vote counts as a majority.

Independents and third party candidates who clearly intend to caucus with a party count as members of that party for this market. For Independents where it is not clear what party they will caucus with, or if they will even caucus with a party at all, I will wait until they actually take office to see if they officially join one party's caucus.

For this market, "winning the majority in an election" means that, if the winners of the election were seated at the exact moment that polls closed, their party would have a majority. In other words, it doesn't depend on anything that happens after the election, even if it affects the party's majority going into the 119th Congress. If for example, Republicans win a 51 seat Senate majority, but then Ron Johnson dies after the election and gets replaced by a Democratic appointee by Tony Evers, it would still count as Republicans winning a Senate majority. But it would not count if he died before the election took place.

And yes, many of these options will resolve N/A since they are all conditional.

See also: /PlasmaBallin/2024-if-party-wins-officechamber-wi-70da5288dfba