Heading into the 2008 election, Americans had been living through a period of extraordinary stability in presidential politics. Fully 34 states voted the same way in each of the four presidential elections from 1992 through 2004, with 18 (plus the District of Columbia) backing the Democratic nominee each time and 16 supporting the Republican. Not since before World War II had so many states voted the same way in four consecutive elections.
In 2008, Barack Obama simultaneously reinforced and shattered this mold. He reinforced Democratic control over the states the party had dominated from 1992 to 2004. Obama won all 18 states (and Washington, D.C.) that voted Democratic in those previous four elections and held Republican John McCain to 45 percent of the vote or less in each of them. That means Democrats have now won states worth 248 Electoral College votes in each of the past five elections.
The Republican electoral stronghold has been smaller in recent years, but the party's hold on it had been even more tenacious. Each of the 16 states that voted Republican in the past four elections had, in fact, supported the GOP candidate in every election since 1980. But Obama this year barreled into that fortress. He captured three of those 16 most reliably "red" states: North Carolina, Indiana and Virginia. (The latter two had not voted for any Democratic presidential candidate since 1964.) In all, Obama won at least nine states that voted for George W. Bush in 2004, including seven that voted for him both times. (McCain leads in Missouri, a tenth state Bush carried both times, pending a final tally of ballots.) Obama's breakthroughs reduced the number of states Republicans have carried in each of the past five elections to 13, with 96 Electoral College votes. That Electoral College base is only about 40 percent as large as the Democratic base over those past five elections.
The charts that follow -- which might be called the National Journal presidential omnibus -- allow readers to track these short- and long-term trends in presidential elections. They report the results by state in the past 20 presidential elections -- since Franklin D. Roosevelt's victory in 1932 established the New Deal coalition that dominated national politics until the 1960s. The 2008 results are the best unofficial tallies available on Nov. 17.
The front page provides a compendium of how each state has voted since 1932; the states can be arranged alphabetically or by the frequency with which they have voted Democratic or Republican over the period. Placing the cursor over any icon on the chart will reveal the results for that state in that year; by clicking on a state, readers can view charts and tables reporting the presidential results for that state over the entire 20-election sequence.
Alternately, by clicking on the vote performance subheading, readers can view the results in any individual election. Again states can be arranged from the most Republican to the most Democratic, organized either by the share of the vote or the total number of votes each party won in each state that year. Also, placing the cursor over any individual state again reveals the detailed results for that state in that election.
Click more options to drill deeper into the data: You can highlight states to see each party's best performance in those states, by percentage of the vote or by raw votes. Clicking highlight year makes it easier to view details for a single election. Finally, you can sort states by the results of a single election to make it easier to compare the parties' performance across elections (for example, comparing how each state's results have changed since the 1988 election).
This article appears in the Nov. 18, 2008, edition of National Journal.