Sen. Mitch McConnell of Kentucky, the Senate Republican leader, has criticized the Obama administration’s proposal to limit federal tax breaks that wealthy people can get for their itemized deductions for donations to charity.

To help pay for a plan to reshape the country’s health-care system, President Obama wants to limit the federal tax breaks that wealthy people can get for their itemized deductions, including donations to charity, starting in 2011.

“With a challenged economy already causing endowments at colleges and universities, charities, museums, and other nonprofits to shrivel up, the last thing America’s nonprofit organizations expected was for the administration to introduce another disincentive to charitable giving,” Senator McConnell said on the Senate floor yesterday.

Mr. McConnell noted that a recent report showed that college and university endowments lost more than 20 percent of their value in a recent five-month period largely as a result of the decline in the stock market.

“The administration’s proposal is a bad one at any time,” Mr. McConnell said. “But now is the worst time of all.”

Senator McConnell said that Americans “don’t understand why charitable organizations and the people they serve should suffer in order to pay for new or expanded government programs.”

He said the proposal could lead to “less money for places like Western Kentucky University, the Juvenile Diabetes Foundation, hospitals, churches, food pantries, and countless other causes that are worthy of our support.”

Mr. McConnell added: “These organizations are hurting enough. The administration doesn’t need to hit them up for more tax revenue while they’re down — and it doesn’t need to blunt one of the things that Americans are most proud of, and that’s their generosity.”

He concluded that “Congress should preserve the full deduction for charitable donations and look for additional ways to encourage charitable giving, not discourage it.”