On Tuesday, NBC's Peter Alexander asked Jeb Bush about how important winning the endorsement of South Carolina Gov. Nikki Haley was to his chances in the state's Feb. 20 primary.

"She is the probably the most meaningful endorsement there is, if she is going to give an endorsement it would be the most powerful, meaningful one in the state," Bush told Alexander.

Less than 24 hours later, Haley threw her endorsement to Marco Rubio, Jeb's fellow Floridian and the man who is well on his way to seizing the establishment mantle that looked to be Bush's birthright when he first got into the race last year.

"I'd rather her endorse me," Bush told Yahoo's Hunter Walker in the immediate aftermath of the endorsement. Well, yes.

Even before the Haley endorsement, Bush's trend line in South Carolina, which he and his campaign have long proclaimed as "Bush country," didn't look good with Donald Trump, Ted Cruz and Rubio slotted into the win, place or show slots.

The simple fact, as I have noted in this space before, is that Bush has to have a top three finish in South Carolina on Saturday to continue on in the race as a serious candidate. And, with less than 24 hours to go before polls open in the state, that scenario looks increasingly unlikely.

The rats appear to be jumping off the ship too. In a piece headlined "Bush Machine Running on Fumes", Eli Stokols wrote Friday:

Even before Haley’s endorsement, several longtime Bush donors were emailing one another Tuesday morning, expressing a collective readiness to intervene and tell Bush, depending on his finish here Saturday night, that his time is up.
“People are going to wait and see what the sequence is in South Carolina, but they’ve put all the players on the field at this point, including W,” one donor on the email chain said. “If he finishes significantly behind Rubio in South Carolina, I think a lot of the people who are personally close to him, including donors are going to say, don’t stay in until money runs out, don’t stay in just to be a spoiler. We’re thinking about legacy now.”

Any momentum that Bush was hoping to build coming off of his fourth place finish in New Hampshire and his best debate performance of the race last weekend was entirely blunted by the Haley endorsement and the pre-obituaries published on Friday.

Jeb Bush, for having to attend your own political wake, you had the Worst Week in Washington. Congrats, or something.

Each week, I award the Worst Week in Washington to an inhabitant of Planet Beltway who stands out for all the wrong reasons. You can check out previous winners or e-mail me with your own nominees.