A day after failing to approve a debt limit bill backed by House Speaker John Boehner, Republicans in the House rallied behind changes to that measure, determined to approve it Friday night and send it on to the Senate.

The changes in the Republican plan center around a Balanced Budget Amendment to the Constitution, which the GOP wants to be approved by the Congress and sent to the states for ratification before a second increase in the debt limit is authorized.

While Democrats scoffed at the change, for Speaker John Boehner, it seemed to move a number of votes into the 'Yes' column for Republicans.

"I couldn't be happier with giving him my 'Yes' vote today," said Rep. Phil Gingrey (R-GA), who had been solidly opposed to his party's debt limit bills, arguing for a link to a balanced budget amendment.

"That's the only way going forward that we can bind the hands of future members of Congress," said Gingrey.

As of now, the plan is for the House to vote late Friday and send that bill to the Senate; it wasn't immediately clear how Senate Democrats would deal with the plan in terms of parliamentary procedure.

One plan would set up a test vote at 1:01 am on Sunday morning, with a final Senate vote at 7:30 am on Monday. Then the bill would go back to the House for a final vote just before the August 2 deadline.

Another plan would have Democrats use a separate bill, giving them more time this weekend to negotiate and finalize a plan.

All of that was in flux.

It means that at some point this weekend, Senate leaders of both parties will have to agree to a package of changes, which seems certain to lead to a weekend of negotiations.

All of it would lead to some white knuckle talks, right up against the deadline for action on the debt limit.

Lastly, the Congressional Budget Office put out an interesting piece of information today, as it reviewed the differences between plans from Speaker Boehner and Majority Leader Reid.

If you take out savings from the wars in Iraq and Afghanistan from the Reid plan, and focus just on how much spending caps in those proposals would save, there is only a $5 billion difference over 10 years.

You read that right.  

Boehner's plan would save $756 billion over 10 years; Reid's plan would save $751 billion over 10 years.  Obviously the two parties might make those cuts in different plances in the budget - but the broader numbers aren't very far apart.