The cloture vote failed 51-45 along mostly partisan lines. Sixty votes were needed to end debate on the Paying a Fair Share Act of 2012 and move it to a vote.
Prior to the vote, Sen. Pat Toomey, R-Pa., ridiculed the reasoning behind the Buffett Rule, saying it would only open the door to higher taxes on the middle class. Toomey called the rule "bad economic policy."
The legislation targeted investment income, requiring it to be taxed at 30 percent, up from the current 15 percent, for those earning at least $1 million a year.
Buffett, ranked by Forbes as the world's third-wealthiest person, has made a point of saying he pays a lower tax rate than his secretary and thinks it's only right for the rich to pay taxes, as a portion of income, comparable to people in the middle class.
In a statement issued by the White House, President Barack Obama said Republicans chose "once again to protect tax breaks for the wealthiest few Americans at the expense of the middle class."
The president said the proposal is "common sense. At a time when we have significant deficits to close and serious investments to make to strengthen our economy, we simply cannot afford to keep spending money on tax cuts that the wealthiest Americans don't need and didn't ask for."
"But it's also about basic fairness -- it's just plain wrong that millions of middle-class Americans pay a higher share of their income in taxes than some millionaires and billionaires. America prospers when we're all in it together and everyone has the opportunity to succeed."
Sen. Joe Manchin, D-W.Va., called the tax system broken.
"We just don't understand why … middle class people are paying so much … They're paying a higher tax rate that someone making $1 million more. That's not fair," he said, denying he would deny anyone success. "When people believe the American dream is in reach, they will all pull a little harder."
Toomey said though Democrats say the rule is targeted at millionaires and billionaires, the revenue it would raise would barely make a dent in the budget deficit and the rule would inevitably be expanded to affect the middle class as well.
Toomey likened it to the alternative minimum tax, which has to be adjusted annually to keep it from affecting too many Americans.
Toomey took issue with Obama's statements the rule would help the economy, saying it would reduce investment, which in turn would lead to a loss of jobs.
Before leaving Colombia, Sunday, Obama said the Buffett Rule was not about income redistribution.
"We're making an argument about how do we grow the economy so that it's going to prosper in this competitive 21st century environment," he said. "And the only way we're going to do that is if people like me, who have been incredibly blessed, are willing to give a little bit back so that the next generation coming along can succeed as well ... .
"The history of the United States is, we grow best when our growth is broad based. We grow best when our middle class is strong. We grow best when everybody has opportunity."
Republicans called the bill a publicity stunt that would do nothing to fix the country's economic problems.
"Democrats can talk about this tax hike until they're blue in the face, but Americans are looking for solutions on jobs, gas prices and the deficit," said Brendan Buck, a spokesman for House Speaker John Boehner, R-Ohio. "And this gimmick doesn't offer a solution to any of them."
Republican National Committee Chairman Reince Priebus said Sunday the bill was simply meant to distract from Obama's record on the economy.
"This is Obama's strategy: Look over here at this shiny object here -- don't look at the big picture, an economy on a brink that I didn't do a thing about and made things worse," Priebus said on CNN's "State of the Union."
A Gallup survey released Friday found six in 10 Americans favor passing the Buffett Rule bill, with 74 percent of Democrats and 63 percent of independents favoring the policy, while 54 percent of Republicans oppose it.
While most Americans agree with the idea of increasing taxes on the rich, it is a low priority, with 1 percent saying the gap between rich and poor is the nation's top problem, the poll indicated.
The top priorities for most were the economy, jobs, dissatisfaction with government and the deficit, Gallup said.
The April 9-12 phone survey of 1,016 adults living in the United States has a margin of sampling error of 4 percentage points.