They're pretty low likelihood events. Wikipedia appears to have a pretty solid writeup of the electoral college system (http://en.wikipedia.org/wiki/Electoral_

They're pretty low likelihood events. Wikipedia appears to have a pretty solid writeup of the electoral college system (http://en.wikipedia.org/wiki/Electoral_College_(United_States)#Alternative_methods_of_choosing_electors http://en.wikipedia.org/wiki/Electoral_College_(United_State... ) which includes the various mechanisms states use to select their electors. The vast majority of the states are winner-take-all, which presumably reduces but doesn't eliminate the possible ways to split 538 down the middle, but some states either only have a single electoral vote or use mechanisms which can divide their electoral votes between the candidates. So, yeah, every election has this chance. Probably isn't going to happen though. This is conjecture, but I'd hazard a guess that a Bush v. Gore style dispute over a single large state which holds the balance of the election is way more likely than an actual numerical tie where the House would choose the president and the Senate the VP.