As usual Matt Taibii has made an insightful article of this predicament: http://www.rollingstone.com/politics/news/how-america-made-donald-trump-unstoppable-20160224

I still dont get why you cant just:

1) Outlaw political ads. Have panel discussions on local or national broadcasts (depending on the scope of the election) to get political recognition. This obviously ties with point 5 and will greatly diminish the need for money/lobbying.

2) Get some more parties that then have to form coalitions to govern or get a majority from case to case. (this would also help with cooperation in the senate/congress). Arguably this will inevitably lead to a more technocratic system (because it is impractical to switch entire government departments each time a new administration takes over), but that should still be much more stable than your current chaos...

3) Get rid of this electoral college nonsense and those weird lines where voters are divided in insane ways... There are plenty of ways that are better than that.

4) Make it mandatory to vote - or at least accept a some kind of punishment if you dont - alternatively make voting day a national holiday or half day off.

5) Dont spend any (media)time on elections until 2 months before the actual election. By all means discuss actual politics, but keep the election nonsense away until voting time.

Most of this works perfectly fine in most of the civilized world.

Edit: I forgot one thing... Whats this voter registration nonsense - If you are a citizen above (xx) age, then you can vote. Obviously you need to have an adress/PO box where the state can send your personal voting card.