The U.S. Senate is nearing a vote on a massive economic stimulus bill.   Tempers are flaring on Capitol Hill, and President Barack Obama is talking tough as the legislative process unfolds.

President Obama has been preaching the need for a bipartisan approach to the stimulus bill.  But now, with so much at stake and scant Republican support, he is changing his tone.

Mr. Obama traveled to Williamsburg, Virginia, and went before a gathering of Democrats from the House of Representatives.  There, amidst the party faithful, he returned to the tough rhetoric of the presidential campaign.

He said he is always willing to listen to new ideas. But he stressed the economic policies favored by Republicans have failed.

"We're not going to get relief by turning back to the very same policies that in eight short years doubled the national debt and threw our economy into a tailspin," he said.

President Obama said the economic situation is dire and getting worse.  And he indicated critics of the bill may not understand all that is needed to turn the economy around.

"You get the argument that this is not a stimulus bill, this is a spending bill," he said.  "Well, what do you think a stimulus is?  That's the whole point!"

Mr. Obama has repeatedly warned of the risk of delay, saying the time for talk is over.

But in the U.S. Senate, the debate continued Thursday well into the evening, with lawmakers asked to vote time and time again on possible changes to the stimulus package.

The Senate Democratic Party leader, Harry Reid of Nevada, indicated he was willing to keep the debate going until dawn if necessary.   He said the world is watching.

"This bill is not only important to our great country.  It is important to the world," said Reig.  "We are the largest economy machine in the world by far."

The bill has gotten larger with each passing day, at one point topping $900 billion.

Republicans say that is far too much government spending. And even party moderates - those most likely to vote with Democrats to pass the bill - say it should be cut back significantly.

The Republican leader in the Senate, Mitch McConnell of Kentucky, says the price tag is way too high.

"The question is not doing nothing versus doing something," he said.  "The question is the appropriateness of almost a $1 trillion spending bill to address the problem."

In the Senate, Democrats need the support of 60 of the 100 members in order to overcome any Republican obstacles to a vote.   Reid has said that number can be reached, indicating a handful of Republicans are willing to side with the Democratic Party majority.   

In the House of Representatives, however, there was no Republican support for the measure.  The House version was approved last week on a strict party line vote.