The former London mayor is trailing Boris Johnson in polls but he won't stop fighting until the last votes have been counted
No one can know precisely where the tracks of Ken's tears take his campaign. Conservative bloggers were shouting jubilantly "to oblivion", even if the experience of lachrymose politicians in the US, from Obama to Clinton, is that they survive such public displays of vulnerability.
The Labour party election broadcast was intended to be emotional, if not a tear jerker. It was framed as an emotional rallying call by Londoners to Ken "to come on" and win for them.
No doubt the tears genuinely reflected his desperation to win, his sense of responsibility.
But the impression could also linger of Livingstone lost in an act of vanity, crying at his own election material.
Moreover, on a day when the party is desperate to shift the debate away from the competing personalities of Ken and Boris – the territory on which Livingstone knows he loses hands down – it might have been better for him to have bottled it all up: this is an election campaign, with a month to go, that Labour has not yet lost.
The Comres poll published by the Standard on Tuesday shows Livingstone six points behind Johnson once second preferences are counted, trailing by a decisive 47 to 53. On first preferences he loses 46-41. Given the pasting he has had in the media over tax, Jews and bankers, that's relatively resilient.
On a range of issues he is well ahead, on others behind only marginally.
Indeed on first-preference votes, the poll shows him outperforming his first-preference performance of 2000, 2004 and 2008. In those three polls he scored a first preference of only 39 or 37 points.
But this could reflect the fact that Liberal Democrat voters have already deserted their party and are backing Livingstone in the first round.
The polls show Livingstone still gains the majority of Liberal Democrat second preferences, but there are just far fewer Lib Dem votes to hoover.
Moreover, it looks on the other side of the ledger as if Johnson's personality can keep the potentially large Ukip protest vote down.
Livingstone faces three specific hurdles in the final weeks. Though he is the oldest politician in the race, he seems to repel his demographic. On second preferences he leads 56 to 44 points with 18- to 44-year-olds, but among older voters the position is reversed; he trails 62 to 38 points among voters aged over 65. There may be more young voters in London, but they are probably less prone to vote.
Ken-mail is going out to 400,000 older voters stressing that Johnson wanted a lower top rate of tax and this is being funded by the "granny tax".
Livingstone's second problem is the more familiar one of carving a message that appeals to the suburbs, specifically to what Tony Travers, the LSE academic, calls "the long-term drift of aspirational C2 voters to boroughs such as Bromley, Havering and Bexley".
These mainly Conservative people vote – in 2008 57.9% of eligible voters voted in Sutton, 54.9% in Richmond, 51.8% in Bromley, 48.9% in Merton and 48.2% in Barnet and Kingston. In Bromley alone Johnson piled up 143,000 votes.
By contrast, turnout in Labour-friendly Newham was 36.1%, making a simple Labour-core vote strategy, based on the inner cities, fruitless.
Livingstone has worked hard to win the suburbs back, launching his campaign two years ago by promising to represent all Londoners. More symbolically a shadow cabinet meeting was held in Bromley starting with a poster saying "£1,000 better off with Ken". His flagship policy to cut fares is aimed at suburban commuters.
Labour claims to have a superior party machine to deliver this message. Inner-city Labour activists have been deployed to the quadrant of Bexley, Hillingdon, Havering and Bromley to locate a long-neglected Labour vote.
Tessa Jowell, the shadow cabinet member, claimed as a result more potential Labour voters have been identified in Bromley a month from polling day than Labour had identified in the borough in 2008 on polling day itself. "Turn-out will be absolutely key in these areas, as well as in the strong Labour low turn out areas".
Yet it is ominous for Livingstone that the Comres poll shows Johnson still ahead in outer London on second preferences by 60 to 40 points.
Travers suggests: "His difficulty is he has a flagship policy on transport that may not be that salient and may not be believed."
Livingstone's third problem is that he is underperforming his party in London. His aides believe they have a month to try to persuade the group that likes Labour but not Ken. Livingstone's aides acknowledge that a straight appeal to vote for him to "send a message to Cameron" about the economy will not work. (Johnson is immunised from Cameron's unpopularity; the blue rosette just endearingly keeps falling off him.)
The more subliminal Labour message is that voters are suffering a government-created squeeze on living standards that Johnson has done nothing to alleviate. Finally the Labour sympathisers opposed to Ken appear to be more concerned by crime and policing issues than most voters. Hence Livingstone is trying to win these voters back with tough messages on rape, burglary, and other crime.
It may all be too late, and after decades on the frontline of London Labour politics, there is an ingrained, settled will about Livingstone in the capital. But he will not stop fighting until the last polling booth closes.