Barack Obama tried to capitalize on the souring economy this fall, and it was reflected in the words he used in his television and radio advertisements during September and October. His use of the word "economy" tripled in ad scripts from August, and he mentioned taxes 24 times in September and 45 times in October while pitching his tax plan and attacking John McCain's policy.

The Illinois senator ramped up his efforts to link McCain to President Bush as well, doubling his use of the phrase "more of the same" from August to October and tripling the number of times he mentioned the current commander in chief by name over the same period. McCain's regrettable proclamation that "the fundamentals of the economy are strong" made its way into the ad rotation as well, with six mentions in September.

Obama also returned to his message of "change" in September and October, mentioning the word more frequently in the final two months than he had during summer advertising.

When the Wall Street meltdown put John McCain in a tough spot, he largely focused his advertising on attacking Obama. But McCain's ads didn't stay focused on one particular point, shying away from the campaign's earlier line of attack that Obama was a "celebrity." McCain instead flooded the airwaves with the word "liberal" as the race came to an end in an attempt to link Obama with Senate Majority Leader Harry Reid and House Speaker Nancy Pelosi and characterize him as a big spender. "Joe the Plumber" also made an appearance in McCain's October ads, as the Arizona senator sought to put an earthy, blue-collar spin on his attacks on Obama's tax policy.

The graphic below shows the most commonly used words from McCain’s and Obama’s advertising for each month, scaled in proportion to frequency.