Final answer:
The single biggest factor accounting for how people decide to vote is party identification. Party identification refers to the political party that individuals align themselves with and often heavily influences their voting decisions.
Step-by-step explanation:
The single biggest factor accounting for how people decide to vote is party identification. Party identification refers to the political party that individuals align themselves with and often heavily influences their voting decisions. When people strongly identify with a particular party, they are more likely to vote for candidates from that party, regardless of other factors such as candidate characteristics, the issues, gender, or ethnicity.