Actually the outcome of compulsory voting with a fine for failure to vote is far more subtle than you think. Firstly it teaches people to vote, so from 18 on you can turn up to the polls and vote, turn up to the polls sign off and put in a junk non-vote or pay the fine. Any choice still gets them to the polls and gets them used to the idea and of course gets the associating with other voters. Secondly and often far more importantly in the US, is the what is required to happen in the election process in order to make the fine valid, the election process must be more accessible to the voters. So weekend elections because it is easier for the majority to vote on weekends rather than weekdays. More voting booths because long lines and queues to drive people away from the pools becomes very corrupt when the result is that they will be fined.
Either the US electoral process changes or the US will continue to fail, rampant political corruption, failing infrastructure, collapse of the criminal justice system, all are signs of an already failed state that is simply waiting for that collapse to propagate throughout the whole US society, the dominoes are already falling.