The key issue of the election will be economics. There is a sizeable reservoir of discontent in the US for the perception that inequality has widened.
The Trump campaign has obviously tapped into this, and has done so successfully.
As for Mrs Hillary Clinton, the perception remains that she is the business-as-usual candidate as far as economic policy is concerned.
The "factor" that might determine the way the election goes could well be simply whether the fence-sitters - those who do not support either Mrs Clinton or Mr Donald Trump - come out to vote, and whom they are going to vote for. According to polls, we are seeing two of the most unpopular presidential candidates contesting the same election. I won't be surprised if voter turnout shows up to be very low.
On Asia policy, the main issue is predictability. With Mrs Clinton, there will be more continuity than change. She was a chief architect of Mr Obama's Asia policy, and many in her foreign policy team are likely to be the same people who worked with her when she was secretary of state.
In the case of Mr Trump, his unpredictability makes it difficult to gauge what his policy on Asia will be. For instance, he talks very tough on China, but few would be surprised if he ends up striking deals with it as well.
Mrs Clinton has vast experience in government and politics. This, one would imagine, is a strength. But it can also be a weakness if the American people feel that the time has come for a change, for a president outside of the usual mould.
Mr Trump is the complete opposite - no experience in government and politics, ergo either a breath of much-needed fresh air or a liability.
Having said that, Mr Trump has managed to really tap into the groundswell of discontent in far more substantial and enduring ways than one would have imagined he could at the beginning of his journey.
As to who will win, your guess is as good as mine!