Majority Leader Rep. Eric Cantor (R-Va.) and Speaker of the House Rep. John Boehner (R-Ohio) say the McConnell backup plan won’t fly. Given everything we know about the House Republican caucus, I think that is right.

So what, then? A senior House aide recounts yesterday’s events for me:

Over the last several days the White House has been walking back the savings on the Biden number. Thursday it was $2 trillion, Monday it was $1.7-1.8 trillion, Tuesday it was $1.6-1.7-1.8 trillion. This morning our staff met with White House folks and the wrap up from that meeting said that the WH is now at $1.5 trillion.

Given those figures, Eric pointed out that wherever we are — it’s a long way from the $2.4 trillion needed to meet House GOP goals of dollar for dollar so he suggested a possible short-term goal in order to avoid default. He then said to the President that since we can only reach so much in savings and you (President) keep moving the goalposts, I will move off my position of only doing one vote in order to avoid default.

The President then got heated. He said he was willing to explain and defend his position. Said he could get well above the numbers the GOP is talking about with revenue increases. Said he wouldn’t be afraid to veto and he will take that message and defend it to the American people. Said if we default it will be a tax increase on every American. Said it is his responsibility is to the American people. Said, I have reached the point where I say enough. Would Ronald Reagan be sitting here like this? I’ve reached my limit. This may bring my presidency down, but I will not yield on this.

Then stormed out of the room and said we’ll see you tomorrow.

So that is the deal then, isn’t it? (You can understand why Obama freaked and left the room.) The House passes $1.5 trillion in cuts and raises the debt ceiling $1.49999 trillion (call it the Ungrand Bargain). If Obama wants to later come back for more on the debt ceiling, he can. But for now the House should vote on principle — no tax hikes and more cuts than the amount of the debt ceiling and send it over to the Senate. In the Senate, perhaps the group of hard-core Republicans — Sen. Jim DeMint (R-S.C.), Sen. Mike Lee (Utah), Sen. Pat Toomey (Pa.) — vote no. So the rest of the Senate then has a choice: default or the House plan.

A senior Senate adviser, considering this idea, says, “I would love to see that and I would love to have that debate in the Senate.”

There you go: The backup to the backup. If the president doesn’t take tax hikes off the table, the House votes the Ungrand Bargain and sends it over to the Senate. And then we wait. And watch.

And perhaps Senate Majority Leader Harry Reid (D-Nev.) then has the problem: His vulnerable red-state Senate Democrats sure don’t want three votes on the debt ceiling. And here is this nice, small Ungrand Bargain that would insulate them from blame for a default and accusations they are tax-hiking spendthrifts. What do you think they’d do?