Tomorrow is Election Day in the US, but a large chunk of the population probably won't vote. Just 53.6% turned out in 2012.

This is a big deal, because it skews results toward certain demographics of Americans. People who are white, over 65, college-educated, or make at least $50,000 make up the largest portion of voters.

But what would the US — home to one of the world's lowest voter turnout rates — look like if everyone cast their ballots? And who would win the presidency this year?

The country's political landscape would be remarkably different, Jan Leighley, a professor of political science at American University, tells Business Insider. Her research focuses on American political behavior and voter turnout.

Here's what would probably happen if everyone voted (Note: In this hypothetical future, we're not talking about a direct democracy, where people vote or write laws themselves. Voters would still choose representatives to do that).

The political landscape would become more liberal — but only on some issues.

Hillary Clinton takes a selfie with supporters in Indiana. Joe Raedle/Getty Images

When more people turn out, laws are more likely to reflect the needs of the majority and less likely to cater to a specific demographic, Leighley says.

Voter turnout in the US is dismal, but Republicans are generally more likely to vote — and they did in this year's primaries. If more Democrats voted, a greater number of local and national policies would be more liberal than they are now, Leighley says. But it would also depend on the issues at stake.

For example, voters are more conservative than non-voters on laws relating to reproductive rights. On laws relating to universal healthcare, voters are more liberal than non-voters.

Candidates would need more nuanced campaign tactics.

Candidates would need to shift their campaign strategies too, Leighley says. They would need to consider that literally everyone is voting — not just the people who normally vote.

For example, as noted by Flash Forward's Rose Eveleth, there's considerable evidence that the wealthier you are, the more likely you are to vote. Candidates would probably cater less to a wealthier demographic if they knew that people from all levels of economic status planned to cast their ballots.

Donald Trump. AP Essentially, candidates would need to develop more complex arguments and persuasion strategies to appeal to different types of voters, Leighley says.

"They would need to take into account that's it's not just the wealthy who will vote, but everyone," she says.

Imagine if every millennial — the demographic with the lowest turnout — voted. Candidates are already using Snapchat and tweeting #yas to appeal to younger voters, but with a 100% turnout, they'd need to get even more crafty.

Would we have laws written entirely in emojis? A nationwide forgiveness for college loans? Vetoes to all hoverboard bans and music pirating laws? The possibilities are endless.

Hillary Clinton would likely win the presidential election.

"If everybody voted," Obama said in March, "then it would completely change the political map in this country."

It's obvious why Democrats would support mandatory voting. Although Obama won two elections with at least 51% of the vote, midterm elections tend to look much different for Democrats. As NPR notes, the demographics that boosted Obama's wins — namely young people, minorities, and single women — are those who are less likely to vote in the primaries, general elections, and midterms. According to a recent Gallup poll, 65% of Democrats and 76% of Republicans said they "will definitely vote" tomorrow.

If 100% of voters turned out, ballots would weigh more heavily toward Democrat candidates. So it'd be easy to predict who would win the popular vote (and likely the electoral college vote) this year: Hillary Clinton.

Although elections would sway toward Democrat candidates, Leighley adds that neither candidate would be able to predict what states they would win based on previous voter turnout stats if everyone voted. More states would swing blue, though.

"We'd have more conflict. Some people who would normally win with 50% turnout would lose," she says. "Power would shift.