What are the rules around poll watching? Plus, 7 other common questions about the election.

Question: Why is it that one candidate can win the popular vote but another wins the electoral vote and thus the presidency?

Answer: That's how the framers of the Constitution set it up.

Question: Is it possible the election will be up in the air and we won't have a president on Inauguration Day: Jan. 20, 2021?

Answer: Even if the election is messy and contested in court, the country will have a president on Inauguration Day. The Constitution and federal law ensure it. Here's what happens after voters go to the polls on Nov. 3:

Question: What is the role of the federal government in elections?

Answer: The federal government has very little role in the elections that choose who is going to run it. Elections are run at the local level and supervised by states. The federal government can help fund elections and set certain standards – such as the requirement that people can register to vote when getting drivers' licenses – through federal law. And of course Washington, D.C. plays a big role in monitoring foreign actors to make sure they don't interfere in elections. But the actual machinery of democracy is run at the state and local level.

Question: What steps have been taken to protect the nation's election systems from potential interference by foreign powers like Russia? Have voting systems been "hardened" in any way?

Answer: Federal, state and local officials prioritized securing voting systems after Russia interfered in the 2016 election, breaking down bureaucracy to improve communication of potential threats, conducting security reviews and installing network sentinels to detect known cyberthreats and suspicious activity.

Question: What's the difference between absentee voting and mail voting?

Answer: There really isn't any difference. Both refer to the practice of filling out ballots that are sent to voters through the mail and returned either that way or at drop boxes or other designated places.

Question: What states vote early and when are these votes counted?

Answer: All states allow some form of early voting, be it by casting votes in person at polling places, voting by mail, or both. But each state has its own rules and timelines on when this occurs. Some started in September. Some don't start until mid-October, or even closer to Election Day on Nov. 3.

Question: If a ballot is tossed because of some issue — maybe a missing signature or it got damaged — will the voter be notified that the ballot's been invalidated? And can the voter cast a new ballot?

Answer: This is a tough one — because the rules vary from state to state. The National Conference of State Legislatures has a state-by-state rundown, but that list isn't comprehensive so voters should check with their local elections officials to understand their options.

Question: What are the rules around poll watching on Election Day in the United States?

Answer: President Donald Trump has been urging his supporters to go the polls and "watch very carefully," raising concerns about possible voter intimidation.