No, it won't be noticed until it actually happens and then it will be immediately rescinded by the states burned by it.
For example, when a GOP candidate loses California by 14% but wins the popular vote by .05% - all California's electoral votes will go to the GOP candidate.
Only then, will the vast majority of dimwits out there realize that they are being disenfranchised and raise the sort of outrage that will knock the house of cards down.
In fact, I would imagine any state faced with this predicament would change the law back, between the actual vote and the meeting of the electoral college.
The US Constitution does not mandate how a state should determine its electoral votes, so these moves are all legal. But a state legislature that negates the majority vote of its constituents will have hell to pay if they don't correct it immediately.
I was about to post the same thought, and am glad I scrolled to the end.
All it will take to end this is for a conservative to win the popular vote and receive the electoral votes from a big liberal state. But, the state legislatures would probably call an emergency session to hastily change the law before it would actually happen.