How long will it be before this charmless pair are voted off?

When Gordon Brown meets Hillary Clinton in Washington this week the pair could be forgiven for consoling one another and asking: "How did it come to this?"

What a difference a year makes. A year ago, Gordon Brown was preparing to grasp the prize he'd waited so many years to hold. At long last he would be Prime Minister; at long last he'd show the doubters they were wrong. For her part, Hillary Clinton was the overwhelming favourite to win the Democratic Party's presidential nomination and, it seemed, quite likely to be the next president of the United States.

How times change. How the mighty have been humbled. The Prime Minister finds himself ten points down in the polls and under siege as fever sweeps the Labour Party and MPs mutter that time is running out for Gordon. For her part, Mrs Clinton needs a miracle if she is to defeat Barack Obama, let alone John McCain in November.

Obama's difficulties with white working-class voters have offered Clinton a glimmer of hope. But it is only a glimmer and even a convincing victory in the Pennsylvania primary next month is unlikely to give her much more than a one-in-ten chance of securing the Democratic Party's nomination. The odds on Prime Minister Brown winning the next British election are still better than that, but lengthening all the time.

Like Clinton, Brown is facing a younger, fresher, more charismatic opponent whose skills he has underestimated. Just as Clinton misjudged the depth of Obama's appeal, so Brown is discovering that David Cameron is a little tougher than he looks. Brown and Clinton were the future once; now they look old and tired and very much of the past.

Politicians can survive criticism, but ridicule generally leaves them helpless. Both Brown and Clinton have entered these dangerous waters and are finding that it's a long way back to shore. Clinton made a fool of herself when she exaggerated her role in the Northern Irish peace process and claimed, contrary to all available evidence, to have faced sniper fire while visiting Bosnia as First Lady. The ridicule she faced was entirely deserved.

Equally, Brown's dithering over whether or not to call an election last year and, more recently, over whether or not he would attend the Olympics has made him, quite reasonably, a laughing stock. Neither Clinton nor Brown has, say, Ronald Reagan's deftness or the lightness of touch to be able to skip past the laughter and emerge unscathed.

No, Brown and Clinton have the misfortune to be operating in an age ill-suited to their talents. They are tacticians, not strategists. Neither seems able to focus on the longer term or the bigger picture. Neither is blessed with an appealing personality, neither seems to appreciate that these days candour wins more points than trying to play both sides of an issue to appeal to as many interests as possible.

In a cynical age, admitting error is more likely to impress than pretending, robot-style, that everything is always under control.

Confronted by adversity, all Clinton and Brown can offer is a promise to redouble their efforts. They will work their way out of a jam.

In another era such Stakhanovite promises might impress the electorate. Not any more. "Is that all you have to offer?" ask voters who sense, not altogether unreasonably, that diligence is the least they have the right to expect.

If hard work alone could extricate a Brown or a Clinton from the mess they are in, they might not be facing such a predicament in the first place. In any case, hard work is irrelevant unless it's accompanied by competence. That, too, has been in short supply in Downing Street and in Clinton's campaign headquarters.

Perhaps the current economic anxiety will persuade voters that diligence and perspiration are enough. But I doubt it. If anything, the signs are that voters want change. These are not comfortable times for incumbents (and in the Democratic context Clinton should be considered the incumbent). Nicolas Sarkozy achieved the striking feat of appearing to offer change and glamour despite representing the incumbent party; Silvio Berlusconi's triumph in Italy is another indication that voters are attracted to candidates that, however flawed, offer something like flair and excitement.

A victory, too, for Boris Johnson in the London mayoral race will only strengthen the sense that glamour and idiosyncrasy are back in fashion.

Indeed, turbulent economic times may demand politicians who offer cheer as well as diligence; inspiration as well as perspiration.

What is Hillary Clinton for beyond the advancement and greater glory of Hillary Clinton? What is her campaign about? She has never given a satisfactory answer. Similarly, what is Gordon Brown's ministry for? What does he want to achieve that his party could not achieve in its first ten years in power? Again, the answer is hard to discern.

As with Mrs Clinton, there is an unfortunate whiff of entitlement about Brown. He doesn't deserve to be Prime Minister because he has a compelling, sweeping vision for the future but because, well, because he's waited a jolly long time and it's his turn to be Prime Minister. But that's not enough. Is there anything actually there? It's hard to say.

George Bush was perceived to be more "likeable" than either Al Gore or John Kerry. Equally, Mitt Romney's undisputed command of policy detail wasn't enough to overcome John McCain's biography and ability to seem a genuine, real-life human being.

When politics is a soap opera voters want character or "authenticity" as well as hard work and ability. Or, to shift television genres, if politics becomes a "reality show" it's surely not a great surprise that humourless, charmless politicians are the first to be voted off the island.

There's a famous episode of The West Wing in which president Jed Bartlett's chief of staff recommends that Martin Sheen's floundering character can regain momentum only if he is prepared to "Let Bartlett be Bartlett". Ordinarily that would be good advice for real-life politicians too. The problem that Brown and Clinton face, however, is that letting "Gordon be Gordon" and "Hillary be Hillary" is exactly what has brought them to their current, awful, shared predicament.