What is a PAC? The major engines behind election fundraising and spending explained.

As candidates enter the final weeks of what has been a fierce campaign season ahead of the 2022 midterm elections, there's no shortage of talk about who has raised the most money and what they're doing with it. 

Fundraising forms a vital part of both parties' battle to win seats in the House and the Senate. It determines how many ads a campaign can afford to produce and run, how many staffers they can afford to employ, and how aggressive they can be with mailing and canvasing efforts. 

Much of the money in politics...