Warren Buffett ups the ante with an offer to donate millions of dollars to help reduce the nation's deficit .. 15 percent of his annual income .. if at least 50 Capitol Hill lawmakers do the same.

Previously Buffett had offered a one-for-one match of any debt donations made by Republican members of Congress, with a three-for-one match for any money Senate Minority Leader Mitch McConnell voluntarily sent to the Treasury.

One Republican, Rep. Scott Rigell of Virginia was already donating 15 percent of his Congressional salary toward national debt reduction, and an "impressed" and "delighted" Buffett will be writing a check for just over $49,000 to match Rigell's 2011 and 2012 donations.

Today, Rep. Rigell met with Buffett for breakfast in Omaha, and the new offer came during a joint interview with Bloomberg TV.

Based on Buffett's adjusted gross income of almost $63 million last year, a 15 percent donation would come to $9.4 million.

Both Buffett and Rigell agree that donations are not going to play a significant role in eliminating the U.S. debt.  Buffett tells Bloomberg, "We need policy and we need it now.  The symbolism may be important.  It certainly may shout out to the American public that we're going to ask a lot of you, so we're willing to be the first in line."

Buffett doesn't blame Mitt Romney for paying a tax rate of around 15 percent, pointing his finger at Congress instead.  "He's not going to pay more than the law requires, and I don't fault him for that in the least.  But I do fault a law that allows him and me earning enormous sums to pay overall federal taxes at a rate that’s about half what the average person in my office pays... He makes his money the same way I make my money ... he makes it shoving around money.”

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