WASHINGTON (AP) — Mitt Romney has given Democrats plenty of support for their claim he manipulated his deductions to keep his overall 2011 federal income tax rate above a certain threshold for political purposes.

The Republican presidential nominee, whose wealth is estimated as high as $250 million, seems hemmed in by a comment to reporters in August that he had never paid less than 13 percent in taxes in any single year over the past 10. Had he taken the full charitable deduction last year, it would have pushed his tax liability below 13 percent.

The former Massachusetts governor and his wife, Ann, could have claimed more in deductions, the trustee of Romney's blind trust said when the candidate's 2011 tax returns were released.

But, Brad Malt acknowledged, the couple "limited their deductions of charitable contributions to conform to the governor's statement in August, based on the January estimate of income, that he paid at least 13 percent in income taxes in each of the last 10 years."