Of all the great things about the game, I had two issues with P4E08 that I hope are addressed in this sequel; I hope they haven't been brought up already (if they have, I would appreciate it if somebody could provide a link or quote to it )
Firstly, one of the few annoying things about P4E08 (mostly a great game) was that underdog candidates would start off with such a huge disadvantage in the general election. For instance, I know Ron Paul would not be as strong against Barack Obama as John McCain, but last time I played as him, Obama won +70% of the vote. Sure, I don't expect Paul to make California a swing state, but I think it is unrealistic for him to start behind Obama in Utah by double digits. After all, there is a significant portion of the population that will vote for a candidate simply because of their party. Certainly Utah shouldn't be 100% guaranteed for the Republican, but it would take a lot more than the nomination of an underdog to make it competitive.
Secondly, I was annoyed that the general election map was always be somewhat similar no matter who the nominee was. For example, Mike Huckabee seems to be just as likely to win New Hampshire as Mitt Romney in the game. We know that would not be the case in reality. Similarly, Huckabee should do much better in North Carolina than Romney.
This issue is even more obvious on the Democratic side. Obama should not be competitive in West Virginia short of either a double digit lead nationally or excessive campaigning and ads there. On the other hand, Hillary Clinton or John Edwards would make it a swing state from day 1 (maybe even have a slight edge).
I would also like to bring up the seeming lack of a home state/region advantage of the Presidential candidate (this directly ties in with what I said above). While it's clear you do have a home state advantage with VP picks, the Presidential candidate doesn't seem to (correct me if I'm wrong), even though they would probably benefit the ticket in their home state/region more than a VP candidate. This would vary from candidate to candidate of course. Some would boost the ticket more in a state that isn't their "home" state. Mitt Romney (in 2012) would get a boost of, at most, a few percentage points in Massachusetts, but he would get a much larger boost in New Hampshire (where he currently lives) and Michigan (where he has strong ties to due to his father).
On the other hand, some would boost the ticket in more than one state. John Edwards would probably boost the ticket in most of the south, particularly the poorer southern states (Kentucky, West Virginia, Louisiana). Some candidates would have both things apply to them. Hillary Clinton would probably give the ticket a larger boost in Arkansas and other "border south" states than in New York.
Simply put, a Presidential candidate may benefit a ticket more in a state other than their home state, and they may benefit a ticket in more than one state, perhaps a whole region (which doesn't necessarily have to be their home region). Yet this effect doesn't seem to be in P4E08. I hope it is in this sequel.
Sorry for the long post (particularly if this has been brought up before).