Actually, I've found my l'il corner of America to be on a par - or actually more educated/active, politically - than, say...Toronto ;D Partisan politics aside (comic is clever but similar ones can and have been done when the Dems win, of course. Indies like me inevitably chuckle - and shiver - at both), the biggest thing that makes the election of dead people or candidates who have withdrawn (the GOP candidate for State Senate in our District withdrew but came within 4% of winning, in this election) happen is the ability to vote a straight 'party ticket' with one tick-box. If they didn't die or withdraw prior to the deadline...they just got voted for, along with all the others running in your electoral district for your party of choice. Add in the truly uneducated voters who just know or like the name, and ones who vote for the dead guy as a protest, and yep, can happen.
Problem is...without the ability to vote a straight party-ticket, even fewer would bother to vote. Even longer wait-times and loooooong ballot forms to complete, inevitably have that result. And voter turn-out isn't great now. So, no one wants to take the slate-vote ability away.
A final thought regarding the election here, and voter turnout - it wasn't entirely the American people having spoken. Big factor was the American people who didn't bother. Overall voter turnout was lousy, but was at least 10% higher in every district tracked by various news agencies, that historically trended Republican (and went GOP again this time in almost every case) as well as some of the big Dem 'unseating' districts. Who can get the vote out, is key. Too many are willing to let other American people speak for them.
Same everywhere though, I think, by all reports. That and voters who let everyone else think for them, too. *sigh*