Under the very best of scenarios, the Senate would be nearing a vote later this evening on Senate Majority Leader Harry Reid’s (D) overly-generous budget proposal, which effectively gives Republicans everything they want (except a constitutional amendment). GOP leaders, in this fanciful scenario, would be delighted by their victory, and the whole nightmare could be over by this time tomorrow.

Obviously, these are not the very best of scenarios.

I’ve been tempted, at various points this afternoon, to post an item updating folks on where things stand, but there really hasn’t been much to say. There have been a whole lot of meetings — some at the White House, most on the Hill — followed by a whole lot of floor speeches. The House had another tantrum — Boehner & Co. appear to be training for next year’s Tantrum Olympics — which was on no consequence at all.

Sen. Orrin Hatch (R-Utah) is urging Americans to call the Treasury Department for reasons I can’t understand; Sen. Tom Harkin (D-Iowa) and Sen. Bernie Sanders (I-Vt.) are pushing the Constitutional Option that the White House lawyers consider illegitimate; and Senate Minority Leader Mitch McConnell (R-Ky.), midday, emerged from a meeting with President Obama and Vice President Biden sounding very optimistic, only to be countered soon after by Harry Reid, who effectively said McConnell’s full of it.

And there’s Sen. Kent Conrad (D-N.D.), who has been seen scurrying from office to office for much of the afternoon, which suggests the Gang of Six plan, or at least parts of it, might be in the mix as part of a larger resolution.

So, what’s going to happen and when? Anyone who claims to know should probably be ignored.

For what it’s worth, about a half-hour ago, CBS News’ Mark Knoller said a White House source “hinted” that “some development” in the crisis “might be forthcoming tonight,” or maybe not.

It’s been that kind of day. This mind-numbing crisis might be resolved within the hour, or the crisis may lead to a default on Tuesday, and no one can say with any confidence which of the two scenarios is more likely.

Update: Sen. John Kerry (D-Mass.) said today the key sticking point appears to be over triggers (or an enforcement mechanism for the next phase of talks). To understand the significance of the trigger policy, refer to the discussion we had on this yesterday. Just as an aside, I’d note that the notion of Republicans crashing the global economy over the kind of trigger included in the debt-reduction deal strikes me as hopelessly insane.

Second Update: As of 9:55 p.m., there’s still talk of a possible Senate vote later this evening, though Reid is also reportedly considering a delay until late tomorrow morning. Republican leaders are, by all accounts, pushing for Social Security cuts as part of a trigger, which is a line Democrats simply appear unwilling to cross. I’m calling it a day; this can serve as an open thread for those monitoring developments.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.