A propos of nothing in particular, I thought I'd bring you a homemade chart. It shows the results of the US presidential elections since 1896, illustrating the percentage of the popular vote the various candidates received.
I made a point of including all third party candidates that received at least 0.1% of the vote as well. My favourite resource for retrieving such results remains Dave Leip's Atlas of U.S. Presidential Elections (though the site's design is by now quite the throwback). A lovely, Old World kind of tool to keep track of the development of all the small parties through the 20th century is this political print by HistoryShots, which is based on the design of an original print doing the same for the 18th and 19th centuries that was created in 1894.
I chose a 100% stacked area chart, when I created this chart (ahead of the 2000 elections; I've merely updated it now) in the hope of making the balance of forces in the vote more instantly clear. It also helps to underline the overwhelming dominance of the two main parties, and the stubborn stability in the distribution of votes.
Click to enlarge etc.
In a system where Electoral College votes are assigned in such a way that Obama was assigned 68% of the electoral vote after receiving just 53% of the popular vote - and where, say, George Bush Sr. commanded 79% of the electoral vote after getting 53% of the popular vote in 1988 - it's sometimes easy to overlook how tenacious a hold both of the parties have on a major share of the electorate. And have had for forever.
No matter how pathetically one of the two parties may perform at the moment, like the Republicans are now, it isn't going to go anywhere. Not unless you dump your electoral system, which I'd applaud ... but that'll be the day!
EDIT: Since the legend is in such a small font as to almost be illegible, and since it might be nice to review the numbers, I've uploaded the data sheet as Excel file on Google Docs.