While there has been no shortage of polls ahead of Tuesday presidential election that suggest the final results will be very close, a breakdown of state polls and other factors tell a different story. Barring unforeseen circumstances, most signs point to a convincing victory for Democratic nominee Hillary Clinton.

Democrats have won the popular vote in five of the last six elections, and nearly all polls have Clinton leading. Clinton leads Republican nominee Donald Trump in 70 of the last 75 polls, with one showing a tie in a four-way race. FiveThirtyEight.com gives Clinton a 69.2 percent chance of winning, while Trump has a 30.7 percent chance.

Voter turnout will be particularly interesting given the high unfavorability ratings of the two major candidates. There could be a record of more than 135 million votes cast in this election—there have already been more than 40 million votes cast thus far—with reports showing Clinton with an edge. She holds a large lead among Hispanics, millennials and has done increasingly well amongst seniors, a base that has traditionally supported Republicans. 

Trump's challenge is both simple and daunting. He needs to sweep key swing states or flip a blue state. Trump seems to have 164 electoral votes sewed up, while Clinton has 260—just 10 short of the 270 needed to win. Battleground states like Arizona, Colorado, Florida, Iowa, Ohio, Nevada, New Hampshire, and North Carolina, which represent a total of 98 electoral votes, have a chance to swing either way. Even Texas and Georgia, though they are expected to still go to Trump, are somewhat up for grabs.

But states that were once purple look increasingly bluer. Pennsylvania, Wisconsin, Michigan, New Mexico and even Virginia are looking like they are solidly in favor of Clinton, and all were carried by President Barack Obama in 2008 and 2012.

Clinton's victory is not a complete lock. There are multiple ways that Trump can pull off an upset, which includes lower voter turnout, and increased support for third-party candidates. There are several candidates running in the election, with Libertarian nominee Gary Johnson and Green Party nominee Jill Stein expected to siphon support from Clinton. 

Johnson's status remains the most curious. It's unclear if the former New Mexico governor will maintain his roughly 5 percent showing. With so many reports of the polls "tightening" many Johnson supporters may consider picking either Clinton or Trump because they have a better chance to win. However, Johnson seems certain to have an improved showing over his 2012 run when he received 1.28 million votes.

It's difficult to project how voters will turn out, but here's a rough idea of what to expect.

Popular Vote Prediction

Clinton: 68.3 million (51.0 percent)

Trump: 60.5 million (45.2 percent)

Johnson: 4 million (3.0 percent)

Stein: 550,000 (0.4 percent)

Others: 350,000 (0.2 percent)

Electoral Vote Prediction

Clinton: 323

Trump: 215

Others: 0