It’s time once again for the State of the Union, that annual ritual of outsized promises and insincere, if thunderous, applause. As I recount here, thanks to a custom initiated by President Jefferson, for 112 years presidents delivered their annual messages to Congress in writing. With each passing year, that custom looks better and better. Would that they’d go back to mailing it in.

As the presidency has grown more powerful over the course of American history, the content and style of the State of the Union has changed accordingly, as Elvin T. Lim documents in “Five Trends in Presidential Rhetoric,” a very interesting article [.pdf] in the journal Presidential Studies Quarterly.

Over time, presidential rhetoric has become less humble, more assertive, less intellectual, less republican (in the small-‘r’ sense of the word) and more populist. And the promises have grown ever grander and less credible. In his half-dozen SOTUs, for example, President Bush has promised, among other things to teach our children well, heal the sick, defend the sanctity of marriage, and bring democracy to the world. Last year the president pledged that, with fedgov’s help, we would “change how we power our automobiles.” (“Wood chips, stalks,” and “switch grass” may be the answer.) And this year, he’ll confirm once again that, as he put it last year, “we are on the offensive in Iraq, with a clear plan for victory.”

Here are a couple of neat SOTU-related links that you can use to track changes in presidential rhetoric over time.

First is the “US Presidential Speeches Tag Cloud,” which “shows the popularity, frequency, and trends in the usages of words within speeches, official documents, declarations, and letters written by the Presidents of the US between 1776 - 2006.” Click and drag through the ages and watch as the word “Constitution” becomes less and less prevalent.

Second is this site, which “provides access to the corpus of all the State of the Union addresses from 1790 to 2006, [and]…. allows you to explore how specific words gain and lose prominence over time, and to link to information on the historical context for their use.” (Via Julian Sanchez).

If you’ve ever thought to yourself, “man, that speech gets dumber every year,” you’re not wrong. The latter site analyzes the SOTUs using something called the “Flesch-Kincaid score,” “which is meant to suggest the grade level in an American school for which the text is comprehensible.” That score’s declining steadily.

Similarly, Lim notes that the quality of argument and the language used in the speeches are becoming more simplistic:

Of course, complexity of language isn’t necessarily a virtue, and the fact that the SOTU’s becoming more comprehensible shouldn’t necessarily be taken as evidence of a national slide toward Idiocracy.

But some of the other trends Lim tracks are discomforting for supporters of limited, republican government, such as the increasing focus on “the children” with “Presidents Carter, Reagan, Bush, and Clinton [making] 260 of the 508 references to children in the entire speech database, invoking the government’s responsibility to and concern for children in practically every public policy area.” Nothing against the cute little buggers, but a properly limited federal government would spend less time talking about them and designed policies that focus on them.

In any event, if you get bored during Tuesday’s speech, use the links above to see how the speech has changed. Or, if not, there’s always the State of the Union drinking game.