At this point, most of the answers are already known for the 2012 election.
Obama will get at least 240 electoral votes and Romney at least 200 electoral votes. They need 270 electoral votes to win.
Right now, it is pretty much impossible for Romney to win UNLESS he gets Florida (29 electoral votes) But getting Florida is not enough to give Romney a win. He also needs to get either Ohio (18) and any two state, or Virginia (13) and three states (or Virginia and Ohio and one other state).
So once again, the nation's future may depend on Florida's votes.
In addition to Florida, Ohio and Virginia, the other swing states are Nevada (6), Colorado (9), Iowa (6) and New Hampshire (4).
Oh, the GOP wishes that Wisconsin (10), Michigan (16, Pennsylvanian (20) and New Mexico (5) were up for grabs. But similarly, the DNC wishes that Arizona (11), Missouri (10), Indiana (11) and North Carolina (15) were up for grabs. But those are all unlikely at this late date. More importantly, anything big enough to move those states would also move Florida, Ohio and Virginia.
Wisconsin, Michigan, and Pennsylvania went DNC for all three of the last presidential elections, and New Mexico only went GOP for Bush's second term. Similarly, Arizona and Missouri went GOP for all three of the last elections, while Indiana and North Carolina did vote Obama, they usually went GOP. Given current polls, those states are not going to move. Indiana and North Carolina are regretting voting for Obama as much as New Mexico regrets voting for Bush.
If I were the GOP, I would spend 30% of my cash in Florida. Without that state, they get nothing. Then about 15% in Virginia and 15% in Ohio. Spend 5% in each of Nevada, Colorado, Iowa, and New Hampshire. That leaves 10% total to be spent shoring up the Arizona, Missouri, Indiana, and North Carolina, and New Mexico and the remaining 10% total in Wisconsin, Michigan, and Pennsylvania. Let the SuperPacs spend general money throughout the other states.
Most importantly, if the the GOP is smart they will get a Floridian as their VP. Rubio is the best shot (I repeat, Rubio is the scariest men in the GOP - he could win in 2016). Double whammy - Floridian and Hispanic. Jeb Bush is another possibility.
The Democrats are a lot harder to predict. They could just dump a crap load of cash into Florida - 50% of it. Then problem is that money can backfire - or worse. But I would spend 20% in each of the the three top states: Florida, Ohio and Virginia. Another 5% each in Nevada, Colorado, Iowa, and New Hampshire. Again, leaving 10% to shore up their Wisconsin, Michigan and Pennsylvania, with another 10% to try for wild shots in Arizona, Missouri, Indiana and North Carolina. Other states get only the Super Pac money.
Now, my own personal prediction is that if Obama wins, it is going to be another landslide. He won't just get barely enough to win (Florida). Instead he will get all the swings states (Florida, Ohio, Virginia, New Hampshire, Iowa, Colorado, Nevada. Over 330 electoral votes. He might even get Indiana or North Carolina. Why? Because lots of states are on the 'tipping point'. When you have multiple states on the edge, then little things will push most of them one way or the other.
But if Romney wins, it will be a closer call. He will win with less than 300 electoral votes. Most probably with Florida, Ohio, Virgina If things turn a little bad, it could be just enough to push just the swing states. It doesn't have to be big enough to push all the others.
Also note, it is just barely possible to get a tie. For example, if Obama gets Colorado and Virginia, but loses every other swing state, then we get a tie.
Note, just because the states tie, doesn't mean the electoral college ties. It is legal for the electors to vote 'the wrong way' in 24 states, including New Hampshire and Iowa. In the other states, they are legally bound - BY STATE LAW to vote that way. But in only two of the states do violations 'cancel the vote'. In Washington Stae they only pay a $1000 fine. In New Mexico, it's a fourth degree felony - he goes to jail, but his vote STANDS.
Assuming the electoral college is tied, that means the House elects the President (one vote per state, which makes it Republican by and the Senate elects the Vice President.
But not all House representatives get a vote. Each state gets a single vote. The single vote is by majority of the representatives. If a state is split 50/50 then they get no vote. To win, you need a majority of the votes cast, not a majority of the possible votes cast.
We have 50 States and the nature of our country has several with few people. The system of each state getting the same vote helps states with small populations at the expense of states with
large populations. This means it will go Republican, by a vote of about 35 to 13 (two tied states), using today's representatives. I doubt it would change all that much after the election.
All of which means, baring a major upset in many congressional races, the tie goes to Republicans.
P.S. It would be the New Congress that makes the vote, not the existing one. That is, we vote in November for both President and Congress. Come December they confirm a tie - after massive re-checking of votes in every swing state. Then in the first week of January, the new congress meets and votes on who the President will be. But that is unlikely to matter - it would take a massive Democrat uprising to change the situation in the House. The GOP would win.