In just over two days we will (probably) know the identity of the man who will be president of the United States for the next four years.

Even though the end of this long, strange trip is nearly here, questions remain about the size and shape of the electorate, the true swing-state battlefield on which President Obama and former Massachusetts governor Mitt Romney will fight over these next two days, and the factors that will ultimately push the sliver of undecided voters to make up their minds.

We lay out five of the most pressing questions.

1. Enthusiasm or organization? Most polls suggest that Republican voters are more amped to vote in this election than are Democrats. According to Washington Post-ABC News tracking-poll data, 80 percent of Republican adults are registered to vote and are absolutely certain to vote or have already voted, compared with 70 percent of Democratic adults. But even the most loyal Romney allies acknowledge privately that the ground operation Obama has built over the past six years — and honed over the past four — is superior to what the Republican presidential nominee has been able to put together since emerging as his party’s pick in April. What Tuesday will prove is what matters more: an enthusiasm advantage or an organizational edge. Conventional wisdom dictates that either could boost a candidate’s showing by a point or two. But if enthusiasm is working for Romney and organization is working for Obama, do they offset each other and turn this question into a push? And if organization and enthusiasm cancel each other out, then who wins?

2. Is the playing field expanding? In the last 10 days of the campaign, Romney and his allies have made investments of time and money in Pennsylvania, Michigan and Minnesota amid polling that suggests all three are single-digit contests. (Pennsylvania appears to be the closest, while Michigan still looks like a long-ish shot.) Romney staged a rally in Pennsylvania on Sunday — his first of the general-election campaign — and his campaign is spending nearly $2 million on TV ads in the Keystone State in the final week. But Pennsylvania has proved to be a Republican trap in recent presidential elections — GOP candidates have been able to earn 48 percent but never 50 percent plus one. (The last Republican to win Pennsylvania was George H.W. Bush in 1988; in the five elections since then, Republican nominees have averaged 43 percent of the vote.) Without Pennsylvania, Romney faces a narrow path to 270 electoral votes — he all but has to win Florida, North Carolina, Virginia and Ohio. A win in Pennsylvania broadens that path considerably.

Explore the 2012 electoral map and view historical results and demographics

3. Where do independents end up? The story of the past several elections has been the wide swings among independent voters. In 2004, George W. Bush (R) lost independents by one point to Sen. John Kerry (D-Mass.). Four years later, Obama carried unaffiliated voters by eight points over Sen. John McCain (R-Ariz.). (The independent swings have been even more pronounced in midterm elections; in 2006, independents voted for Democratic candidates by 18 points but four years later went for Republican candidates by 19 points.) In Post-ABC tracking polls over the past 10 days, Obama has regularly trailed Romney among independents by double digits. But in Saturday’s tracking, the incumbent had pulled into a tie with these voters. If independents do move to Obama in the race’s final hours, expect much focus to fall on Hurricane Sandy and Obama’s handling of the disaster. Independents love the idea of politicians working together to solve problems, and Obama’s trip to New Jersey to tour the devastation with Republican Gov. Chris Christie could have moved some unaffiliated voters to his side.

4. Will young people support Obama again? And in what numbers? One of the biggest myths of the 2008 election was that Obama drastically increased the number of 18-to-29-year-olds who voted. In 2004, 18-to-29-year-olds constituted 17 percent of the electorate. They made up 18 percent of it in 2008. The difference? Kerry won that youthful age group by nine points nationally; Obama won it by 34 points. Given that, the key for Obama on Tuesday is not to expand the share of the electorate that 18-to-29-year-olds make up but rather to ensure that it doesn’t dip significantly, with the young people who vote doing so in something close to the percentages they did four years ago. Polling suggests that enthusiasm (as measured by likelihood to vote) among 18-to-29-year-olds has drifted off from four years ago, but the Obama campaign has placed a giant bet on being able to motivate and turn out these younger voters.

5. How big is the gender gap? Democrats have spent lots of time in this election driving a narrative that Republicans are conducting a “war on women,” pointing to some of the policies espoused by GOP candidates on contraception and abortion — not to mention decidedly impolitic comments made by Senate candidates in Missouri and Indiana on rape. But national polling suggests that Romney is trailing Obama by mid- to high single digits among women — a margin that would rank among the smallest gender gaps in modern presidential history if it holds. McCain lost women by 13 points in 2008, George W. Bush lost them by 11 points in 2000, and Bob Dole lost the female vote by a whopping 16 points in 1996. Democrats insist — and some polling data confirm — that Romney is having more trouble among female voters in targeted swing states where the Obama ad onslaught on Romney’s record has been focused.