I’ve seen several people claim that their state’s vote for the US presidential election doesn’t matter because their district is gerrymandered, which does not matter for most states.
Most states use the state’s popular vote to determine who the entire state’s electoral college votes go to. No matter how gerrymandered your district is*, every individual vote matters for assigning the electoral vote. [ETA: Nearly] Every single district in a state could go red but the state goes blue for president because of the popular vote.
*Maine and Nebraska are the notable differences who allot individual electors based on the popular vote within their congressional districts and the overall popular vote. It’s possible there are other exceptions and I’m sure commenters will happily point them out.
Edit: added strikethrough to my last statement because now I have confirmed it.
Of the 50 states, all but two award all of their presidential electors to the presidential candidate who wins the popular vote in the state (Maine and Nebraska each award two of their electors to the candidate who wins a plurality of the statewide vote; the remaining electors are allocated to the winners of the plurality vote in the states’ congressional districts). (source)
Not nationally, but because Maine uses both Instant runoff voting for presidential elections, and the Congressional district method of assigning electors, it’s mathematically possibly for Maine to split its electors 2-2. eg, the Republican wins both districts individually, while the Democrat wins statewide. Not this year though – needs a competitive 3-way race so the runoffs matter.