SUMMARY: In new TV ads, McCain and Obama make claims about taxes and Fannie Mae. We find they're both exaggerating.

With the economy dominating the headlines, the presidential campaigns unleashed new ads focusing on the candidates' tax plans (Barack Obama) and an I-told-you-so claim about Fannie Mae (John McCain).

We found McCain's ad was right that he spoke up two years ago on the problems at Fannie Mae and that Democrats opposed the bill. But he exaggerates his role and overplays the Democratic opposition. We gave his claim a Half True.

Likewise, we found Obama was cherry-picking his numbers to back up a claim that his tax plan "offers three times as much relief to the middle class as Sen. McCain's." That depends how you define middle class — and for which year in a possible Obama presidency. We gave that one a Half True.

We also found Obama was right that under his plan, senior citizens would not have to pay income taxes if they earned less than $50,000. We rated that one True.