Love it or hate it, the Electoral College is the turnstile to the White House, and that means that a handful of states will swallow up most of the attention on Election Day and, if necessary, in the days that follow as ballots are counted.
Here are some key cities and counties in four states that will play a crucial role in determining the winner. These states and municipalities will also be closely watched for how they handle what is expected to be historic turnout, including unprecedented numbers of mail ballots.
Of course, not all will swiftly meet the surge of mail ballots. Florida and Arizona, for example, will begin counting those ballots well before Election Day, and are expected to report results more quickly. Pennsylvania and Michigan cannot begin counting until Election Day.
Of the three Northern industrial states that Donald J. Trump flipped in 2016 after they had long voted for Democrats, Pennsylvania is the closest entering the final stretch. With three million mail votes expected statewide, in the first year in which all Pennsylvania voters have that option, full results may not be available for days after Nov. 3.
Philadelphia: Can Joseph R. Biden Jr. re-energize Democrats’ core supporters, Black voters, after Hillary Clinton’s lackluster showing here in 2016? City officials have been concerned about supporting in-person voting this fall. Philadelphia had to consolidate its usual 830 polling locations into 200 for the state’s primary in June, partly because of a poll worker shortage. It aims to open about 800 in November, but is still short thousands of workers.
Bucks County: The vote-rich Philadelphia suburbs have been inundated by a blue wave since 2016, but Bucks County, north of the city, remains contested territory.
Westmoreland County: Mr. Trump won this large county outside Pittsburgh by a bigger margin than any major county in the state. If he pushes his vote share even higher, it may indicate he is turning out enough white voters without college degrees statewide to carry Pennsylvania once again. But voters in larger counties like Westmoreland might find it harder to turn in absentee ballots if they don’t trust the Postal Service; though the State Supreme Court ruled in favor of allowing officials to set up ballot drop boxes, a pending federal case could eliminate that option.
This is another of the “blue wall” states that Mr. Trump won in 2016, along with Michigan. In polls, Wisconsin is looking slightly better for Mr. Biden than Pennsylvania, but the president still has a path here.
Waukesha County: The suburbs of Milwaukee historically deliver Republican landslides. G.O.P. voters who were lukewarm about Mr. Trump in 2016 have fallen in line, but Democrats have made inroads and Mr. Biden is tightening the margins. Waukesha is one of the Republican-leaning counties that is bucking a national trend and showing big interest in voting by mail, with more than 91,000 ballot requests as of Monday.
Winnebago County: A large bellwether county in east-central Wisconsin, Mr. Trump won it in 2016, but in 2018 Democrats running for governor and the Senate performed much better.
Dane County: The home of the University of Wisconsin has seen chart-topping turnout for Democrats in recent elections. How much higher can they run up the score to counter Republicans in rural counties? Madison, the county seat and state capital, was among the population centers that most successfully responded to the coronavirus outbreak during a statewide election in April, closing just about a third of voting locations. In November, officials don’t anticipate having to close any. But concerns remain regarding mail-in ballot confusion; the deadlines for ballots to be received are still being fought over in court.
Although Mr. Trump won the state by 3.5 percentage points in 2016, he trails Mr. Biden in polls, largely because the state has a smaller share of white voters without college degrees than the Midwest battlegrounds, as well as a larger Latino population.
Maricopa County: About six in 10 Arizona voters reside in this sprawling county that includes Phoenix. Liberal newcomers and Latinos have powered Democratic victories there since 2016. Both parties are comfortable with mail-in ballots, which three-quarters of Arizona voters have used in recent elections. Rule changes this year let officials start processing mail ballots 14 days before Election Day, which will speed their reporting on election night.
Elections in Florida are won by running up the score in favorable terrain while losing more closely in hostile precincts. It’s a battle for margins more than for swing voters.
The state has more experience processing and counting absentee ballots than some others: Nearly one in three ballots were mailed in 2016, and so far 4.5 million voters have requested absentee ballots. But the state’s history of razor-thin elections could mean that common errors on those ballots — missing signatures, mismatched signatures or missed deadlines — could be the subject of legal challenges.
Miami-Dade County: The biggest county in the state and a Democratic stronghold, it is not a county Mr. Trump will hope to win. But if he can increase his support among Hispanic voters over 2016, particularly non-Cuban Hispanics, it would all but block Mr. Biden’s path to winning the state.
Sarasota County: With nearly four in 10 residents over 65, this county presents a test case of how much Mr. Biden can eat into Mr. Trump’s support among older Floridians. Four years ago, Mr. Trump carried Florida seniors by 17 percentage points. Recent polls show voters over 65, usually a reliable Republican bloc, evenly split between the candidates.