In 2016, Donald Trump carried Pennsylvania by more than 44,000 votes – a 0.7% margin of victory. In 2020, Joe Biden’s margin was 81,000 votes – a 1.2% margin of victory. A similar close margin looks to be in the cards for 2024. Any measurable movement in either direction could tip the balance. If Pennsylvania moves back into Trump’s column, then President 45 probably becomes President 47.

Absent some unforeseen major event, it will be a tight race. Neither Trump nor Kamala Harris is likely to carry Pennsylvania by more than 2 percent. It’s said that “a single grain of rice can tip the scale.” What are the single grains of rice that might do so in Pennsylvania, changing the race by even a few tenths of a point?

Mail-in voting and the GOP. For the first time, Republicans are launching a major effort to encourage more of their voters to vote by mail. The goal is to grow the number of GOP votes overall, not just shift them to mail-in.

In 2020, Biden got 1.3 million more mail-in votes than Trump. Put another way, Trump “won” on Election Day by 1.2 million votes, but by then he was too far behind. The ratio of Democrats to Republican mail-ins has been 5-1. Can the GOP get that margin down to, say, 3-1?

Black voters. Since 2016, Trump has worked hard to campaign in places like North Philadelphia, looking to build bridges to black voters and talk about the challenges that city residents face, from crime to the economy. Can he grow his support to 8, 9, or even 10%?

But this is about both turnout and margin of victory for Harris, especially in Philadelphia, Pittsburgh, and Harrisburg. Democrats face a challenge in getting black voters out to vote, particularly in working class communities. Inflation is real and very much a part of their lives. Crime affects how they live and feel going out at night. And the schools in their neighborhoods all too often are failing. No surprise, then, that turnout has been a growing problem. We’ll see if Harris can turn that around.

Hispanic voters. It’s a national story. It’s an Arizona story. It’s a story in Reading, Pennsylvania – and beyond. More Hispanic voters are embracing the GOP, or, at a minimum, they feel uncomfortable with today’s Democrats. From issues like the role of parents and respect for religion, to say nothing of the top issues – education, the economy, and safety and security – more Hispanic voters sense that the Democratic Party doesn’t speak for them. Many even feel that Democrats actively oppose what they hold dear.

Yet, the GOP hasn’t sealed the deal. There are concerns about how welcome Hispanics are in the party. Trump has campaigned in Hispanic communities and made outreach a part of his effort. To the surprise of many in the legacy media, Trump’s message on securing the border is not off-putting to many legal immigrants and second- and third-generation Hispanic-Americans – though, at times, his word choice gives some pause.

Hispanics are not a monolithic voting bloc, and they live all across Pennsylvania. Reading is nearly 70% Hispanic now. In 2020, Biden’s margin of victory in Reading was about 25% less than Hillary Clinton’s in 2016. Can Harris hold the line against further erosion, or will Trump grow his vote share in Reading and in the Hispanic communities in Philadelphia, Lancaster, and the Lehigh Valley?

Jewish voters. Prior to October 7, 2023, this would not have been a Top 5 voter bloc to watch, despite Trump’s focus on Israel’s security. The horrors of October 7, and the political responses since then, will have an electoral impact.

Here, as with black and Hispanic voters, Trump is fighting on the Democrats’ turf – but the Democrats have reason to worry about Jewish Democrats voting Republican, or not casting a ballot for federal races and voting only for local politicians. Harris losing even 10% of Jewish support would be disastrous.

Democrats are trying to go on offense with two communities: suburban woman and rural voters. Here, too, they’re playing at the margins – knowing that even minimal growth in support can make a difference.

In the suburbs, their strategy is like pressing olives, looking for just a little more oil. If they “press” a fourth time, can they get even 20,000 more female votes in the suburbs? In rural Pennsylvania, they’re trying the John Fetterman strategy: trying to reduce the margins of their losses in rural counties. Bradford County is a case in point: in 2020, Trump carried it by 45 points, but Fetterman lost it by “only” about 40 points in 2022. Can the Democrats squeeze out an extra few thousand votes in the Philadelphia suburbs and a few hundred votes in each rural county?

On Election Night, look to a few bellwether counties.

Bucks County: a virtual tie or better for Trump would be a win, while anything above a 4% margin would be a win for Harris. Lackawanna: Joe Biden’s home turf, and the outlier in an otherwise red zone of counties. With Biden gone, can Trump grow his support there? Erie: the most northwest county in the state. It’s Pennsylvania in a nutshell. In 2016, Trump won it by 1.6%, or 1,900 votes. In 2020, Biden won it by 1%, or 1,400 votes. As Erie goes, so may go Pennsylvania – and the nation.

Both sides are trying small steps to tip the scale a percentage point or two. Can the GOP succeed at mail-in voting, or gain any support among traditional Democratic voters – blacks, Hispanics, Jews? Can Democrats “press the olive” one more time in the suburbs, or make any inroads in small towns?

A single grain of rice may tip the scales – and win the presidency.

Guy Ciarrocchi is a Senior Fellow with the Commonwealth Foundation. He writes for RealClear Pennsylvania and Broad+Liberty. Follow Guy @PaSuburbsGuy.