Image copyright Getty Images Image caption "Please clap"

The Kentucky senator, Rand Paul, who pulled out of the presidential race on Wednesday, had a slogan "Stand With Rand". But not enough people did. So he quit the field.

Jeb Bush's campaign is winning even less support (he trailed well behind Rand Paul in Iowa), but he is not quitting. So perhaps his campaign should now carry the moniker "Ebb with Jeb", because while he is still in the race, it is reaching the lamentable stage.

If this were a TV medical drama and not a political race, the scene that we would have played out is a bunch of concerned physicians, stethoscopes round their necks, wearing pristine white coats, looking concerned peering over a comatose, perfectly still body, while the monitors at the bedside barely flicker.

And eventually one would pipe up, his brow furrowed and exuding quiet concern: "I think we should pull the plug."

Run the theme music and titles.

OK - I know, I know. You're going to throw Mark Twain at me and "reports of my death are much exaggerated". And, of course, Jeb! (surely one of the most misplaced exclamation marks in political campaigning history) might come back.

Image copyright Getty Images Image caption A slogan intended to connote excitement hasn't done the trick

He might emerge from the rubble, shake off the plaster dust, standing taller and walking stronger than he has done hitherto. But the auguries are not good.

Take this. Yesterday he made a speech to supporters in New Hampshire.

He was making a point on national security and he was coming to the end of his stirring paragraph. The crescendo. The peroration. The climax. The moment when soaring rhetoric takes the audience to a different place and they find themselves applauding and cheering wildly, almost unconsciously.

And what happened? The audience sat there in stony silence. So what did he do? He said: "Please clap."

That is like a comedian telling his audience to laugh at an unfunny joke. A teacher telling unruly kids in a lesson to enjoy quadratic equations. A boss telling staff that they ought to say "thank you" for the pay cut being introduced.

Sorry Jeb, just because your name is Bush doesn't mean you have an entitlement to anything in this race.

Actually that's not fair. He is clever and has carefully considered policy positions. And he was a highly regarded governor of Florida - someone who had a solid record of achievement during his period in office.

Image copyright AFP Image caption Bush made an impression in the last debate - the one without Trump

I was at his campaign launch last summer at Dade College in Miami, and came away thinking that though he wasn't a great speech maker, he could well win the Republican nomination.

His audience was diverse, the enthusiasm for him was real and he seemed to reach parts of the Republican party that others struggled to.

In a "normal" election cycle he might have actually flourished. But Donald Trump has seemingly ended all that.

The charge that he is low-energy seems to have stuck. The whole Trump tactic of treating Bush more as an object to be pitied than feared seems to have struck a chord.

It was no coincidence that Bush's finest hour in this campaign came at the latest TV Republican debate, which Trump boycotted.

With Trump not there to bully and belittle, Jeb seemed to find his voice. But it might be too little, too late.

And when his staunchest supporters like Senator Lindsey Graham are saying that Bush will be "toast" if he doesn't do well in New Hampshire, you know that it is make or break.

All of which brings us to money. Jeb, through his own fundraising efforts, and that of Right to Rise, a pro-Bush super PAC, has raised money beyond the dreams of Croesus.

Image copyright AP Image caption Jeb can't count the votes of canine supporters

And he has spent liberally. While the spending efforts of Jeb's own campaign in the last month won't be released for a few weeks, Right to Rise spent $14m on advertising in Iowa. He received just over 5,000 votes. In other words $2,800 (£1,934) was spent for every vote he received.

I dug out the figures spent by the Conservative Party in the UK in the last general election, in May last year. They spent $24m and in return, received 11.3 million votes. In other words, just over $2 per vote. The difference is just jaw-dropping.

From which, I draw two conclusions. The first is that there are truly staggering sums of money involved in US politics. Yeah, yeah, tell me something I don't know.

But the second - more satisfying - conclusion if you are a passionate believer in the power of democracy is that, to misquote the early Beatles song, "money can't buy you votes".

Or as one of the fathers of modern US advertising, Bill Bernbach, would have put it - "No matter how skilful you are, you can't invent a product advantage that doesn't exist. And if you do, and it's just a gimmick, it's going to fall apart anyway."

In other words you can't sell a bad product.