In the final run-up to Election Day, campaigns, parties and outside groups are rushing to spend unprecedented cash on hand.
Most voters have already decided whom they want for president, experts say. Will undecideds vote at all?
More than 100,000 political ads have aired in Iowa so far, up 65% on 2016.
More women are contributing money, and more of that money is backing female candidates.
When President Trump, like his predecessors, stumps for local politicians, local taxpayers foot the bill.
Campaign watchers estimate the nominees have to raise about a billion dollars.
He outspent all the other GOP candidates in Iowa, but only brought in about 5000 votes