The default asteroid’s so close now that you can actually see its shadow.

The House Rules Committee will not report out a rule Tuesday evening on House Speaker John Boehner’s deficit-reduction package to lift the debt ceiling, postponing a scheduled Wednesday vote on the plan, according to three GOP sources. An announcement is expected later tonight.

A Twitter pal wondered whether this means they’ll have to break their pledge about waiting three days before taking up legislation. Alas, that one’s already been broken. Supposedly they’re delaying the vote because they’re scrambling to find new savings and rewrite the bill after the CBO score came in too low, but there may be a bigger problem:

Speaker John Boehner and House GOP leaders engaged in a furious last-minute lobbying effort inside and outside the Capitol on Tuesday evening to pass their debt ceiling package, but the outcome of that vote remains far from certain, according to Republican lawmakers and aides…

Boehner was hauling members who are undecided or leaning “no” into his Capitol suite for one-on-one meetings, using the time-honored tradition of his office to twist arms and win votes. Boehner had “made progress,” but late Tuesday there was speculation they may have to delay the vote…

No official whip counts are available, although some Republican lawmakers estimate 40 to 50 GOP lawmakers are no’s or undecided heading into the dramatic floor fight.

If House Democrats stick together in opposition, which they have every reason to do with Reid’s bill waiting in the wings, then the GOP can only afford to lose 20 or maybe 25 Republican votes, assuming they can pick off a handful of Blue Dogs. Over at the Corner, Andrew Stiles’s whip count has 21 confirmed or presumed no votes. They’re down to the bone, in other words, and that’s before the full effect of the shockwave from today’s disappointing CBO score has been felt. There are already five Republican no votes in the Senate, too: In addition to Lindsey Graham, who’s clearly trying to cover his flank ahead of his reelection campaign, DeMint, Rand Paul, Mike Lee, and David Vitter(!) sent out a letter today urging House Republicans to defeat Boehner’s bill. Even if it gets through the House, then, it would start with just 42 votes in the Senate. Are 18 Democrats prepared to vote yes when they have Reid’s bill as an alternative?

Assuming the new vote is set for Thursday, the calculus I described here has changed. The plan before was for the House to go first; if the GOP succeeded in passing Boehner’s plan, then the Senate GOP would filibuster Reid’s bill. That would leave Boehner’s bill the only game in town, which might shake loose enough Senate Democrats to pass it in the name of averting default. Now, thanks to the delay, the Senate might go first. What does that do to the votes of moderates like Scott Brown and Murkowski, who may now be convinced that Boehner’s bill can’t get out of the House and that the only thing standing between the U.S. and default is Reid’s plan? Reid, after all, needs only seven Republicans; if he can get through the Senate, there may be 25 GOPers in the House prepared to bite the bullet.

Exit question: Now that we’re so close to the wire, with both bills possibly DOA in their own chambers, will Boehner and Reid simply merge their bills somehow and roll them out jointly on Thursday? I’m thinking that may be the only way to get to 218 and 60.

Update: Note to hawkish Republicans who are thinking of voting for Reid’s bill: You sure?