The controlled opposition party makes dang sure that the only other option in major elections is "more of the same". (i.e. Democrats generally fail to clean up whatever mess the last Republican administration made, continue funneling money to Israel, yaddah yaddah, and don't to a whole lot to help the working class.)

A lot of people are completely fed up with "more of the same", so they voted for the clown or didn't bother to show up.

Don't blame the voters when they were never given a real choice.