Title text: It'd be great if some news network started featuring partisan hack talking heads who were all Federalists and Jacksonians, just to see how long it took us to catch on.
Click the date above the comic to go to the xkcd page, and there is a link to the much larger version. Go find something interesting, don't worry, the wiki will still be here.
It appears that the upcoming 2012 election has put Randall into a political state of mind, as this is the second comic in a few weeks that has dealt with political history (1122: Electoral Precedent). As with that comic, this comic goes through the entire history of the U.S. Federal Government. Also notably, Randall makes a number of observations that are akin to the type of observations Randall denounces in 1122 (e.g. for 1928, Randall notes that no Republican has since won the presidency without a Nixon or a Bush on the ticket).
 U.S. Federal Government
In the U.S. Federal Government, one of the checks and balances is a bicameral United States Congress, which consists of two "houses": the Senate, its "upper" house; and the House of Representatives ("the House"), its "lower house". The Senate consists of 2 senators elected from each state (thus 100 total), while the House consists of 435 voting representatives (a number decided upon in 1911 by law) whose apportionment is split between the states proportional to their population; although each state gets at least one (the House also has non-voting representatives from unincorporated territories like Puerto Rico and the District of Columbia). Every ten years, the House is reapportioned based on the latest census. The most populous state as of 2012 is California which has 53 seats in the House. Senators serve 6-year terms with elections held every 2 years for one-third of the seats. Members of the House (called Representatives or Congressmen/women) serve 2-year terms with all of the seats contested every 2 years.
In order for a bill to become a law, it must be passed by both the House and the Senate. In a way, this theoretically ensures that the bill is supported both by the majority of states (the Senate), and the majority of the population (the House). The President may then sign the bill into law, he may "veto" the bill, or he may do nothing, in which case it becomes a law if and only if Congress is in session after a waiting period of 10 days (not including Sundays).
 Political ideologies
In politics, there is a scale that represents the political beliefs of a politician. The scale goes from "left" to "right" of "center" - which generally describes a balancing point of beliefs (sometimes called "left-wing" or "right-wing").
The "left" is a general belief in social justice, and is sometimes associated with socialism. Modern left-wingers generally mandate equality, and support policies like welfare and government-subsidized healthcare. This trends toward having a larger federal government. In the U.S., "liberal" is a term often used to denote left-leaning tendencies.
The "right" generally believe in conserving the social and economic status quo, which is often termed conservative. This trends towards having less regulation and thereby a smaller federal government. The goal is to keep the nation stable, and reducing the interference by the government with a person's wealth. This ostensibly means lower taxes, because the government does not provide as much.
Politicians typically align themselves into groups of similar beliefs and positions called "parties". In the U.S., there have generally been two dominant parties (although there have been times where three or more parties have shared roughly equal influence and support). In today's politics (which is apparently known as the fifth era of political parties, or Fifth Party System, as noted on the outside edges of the comic) of the two current primary U.S. political parties, the Democrats are the left-leaning party, and the Republicans are the right-leaning party. The dominant parties are generally considered "moderate" in their left- or right-wing leanings, as either party appears to requires the support of a majority (or a few percent under) of voters to win In actuality a process called gerrymandering where election boundaries are redrawn to allow a political advantage to the party currently in power. Thus a popular majority state wide or any ratio of votes to representatives will not nescisarily be reflected in delegates awarded. An example being the republicans REDMAP 2012 report (). Smaller parties often run candidates with more extreme views, but such candidates rarely win, due to a more limited number of possible supporters ensuring that even a relatively large minority would have zero chance of representation. (see Duverger's law).
 The comic
The comic effectively consists of three separate charts: The left- and right-hand charts are the main charts; they represent the Senate and House respectively, and purport to show the left- and right-wing leanings of each legislature through U.S. history. There is a legend on the right that sets out fairly clearly how the charts work, but basically Randall has split each wing into three levels including the very moderate or "Center" right or left, and the more extreme or "Far" right or left, as well as the average left and right, without prefix. A dotted yellow line represented the balance of power in each legislature, and white lines represent the leanings of certain notable people including presidents.
Some presidents are not indicated, because they were never senators or congressmen (most of these were state Governors, such as Clinton, Bush and 2012 candidate Mitt Romney). As may be noted from the chart, Barack Obama is considered "left" while Paul Ryan is considered "far right". It's also notable that the "center right" ideology appears to be completely eradicated from the House and is waning in the Senate (although a similar trend is shown around 1900 with the centrists making a comeback thereafter).
On either side of these charts, there are descriptions or explanations for expansions and contractions of each ideological group.
The center chart appears to primarily act as a timeline. Each president is listed with their leanings indicated by a left or right arrow. Wars are shaded in grey. Other notable events are also indicated. On either side of the center chart (although somewhat mixed in with the aforementioned Senate/House explanations), there are also references to the primary parties of each era showing how they evolved (left-leaning parties on the left, and right-leaning parties on the right).
Finally, there's a little extra commentary on the right side, below the legend.
- A history of
- The United States Congress
- Partisan and ideological makeup
- [The comic is divided into three massive sections, SENATE, PRESIDENCIES, and HOUSE. Timelines run backwards down the page between each section. In the HOUSE and SENATE sections, shifting, curving red and blue areas of different brightness illustrate the shifting balance of power between "Members of Left-Leaning Parties" and "Members of Right-Leaning Parties". Under PRESIDENCIES, different administrations are labeled and wars are shaded in gray. There are notes throughout all sections.]
- [There are additional notes on the right.]
- [Square containing ribbons of color merging upwards with larger areas]: Branches join in when new members enter Congress and cause an ideological bloc to grow. (Note: If the new member is elected as another retires from the same ideological bloc, no change is shown.)
- [Square containing ribbons of color splitting off from larger areas]: Branches split off when members leave Congress, causing their ideological bloc to shrink. (Note: If the new member is elected as another retires from the same ideological bloc, no change is shown.)
- [Square showing yellow dotted line crossing from red to blue area]: The yellow line marks the midpoint, which indicates which side has control of the chamber.
- [Square in which curve briefly separates from blue area]: If a bloc loses members in one election and gains them in the next, the exiting stream may rejoin. This does not necessarily mean the same people returned.
- [Square showing white dashed line labeled Lyndon Johnson on top of ribbon merging with main area]: Future (and past) US Presidents who served in Congress are shown with white dashed lines. Other noteworthy members are shown with thin solid lines.
- [Square in which tinted area marked "Whig" sits over mix of red and blue areas]: Tinted white outlines mark the approximate membership of some of the smaller political parties.
- HOW IDEOLOGY IS CALCULATED
- Each member of Congress is assigned to an ideological category using DW-NOMINATE, a statistical system created by political scientists Keith Poole and Howard Rosenthal. This system rates each member of Congress's ideological position position [sic] based on their votes.
- DW-NOMINATE is purely mathematical and involves no judgement on the content of bills. Instead, members of Congress are placed on a spectrum based on how consistently they vote together.
- While people argue that ideology is many-dimensional, Poole and Rosenthal found that nearly all Congressional voting behavior - especially in the modern era - can be accurately predicted by using just one ideological variable.
- This variable turns out to roughly correspond to position on the classic economic liberal/conservative spectrum.
- Because members of Congress have served in overlapping terms with past members in a chain back to the first Congress, the system allows comparison of ideology across time - even accounting for individual members' ideological drift. (Note: Scores are comparable across time but not between chambers.)
- For more detail, see Poole and Rosenthal's website, voteview.com.