The number of eligible Latino voters has reached a historic high, with almost 24 million able to participate in November's presidential election, an increase of 4 million over the previous ballot in 2008.

The new figures, released by the Pew Hispanic Center, underline the seismic demographic shift that is transforming the electoral landscape of the US. Over the past 20 years the number of Latinos eligible to vote has grown steadily and steeply, from 8.3 million in 1992 to 14.5 million in 2002 and 23.7 million in 2012 – some 11% of the current electorate.

That is in turn a reflection of the growing numeric presence of Hispanics, who now stand as America's largest minority. Last year Latinos accounted for almost 17% of the population – some 52 million people.

But Pew's research also underscores the unfulfilled nature of Latino political power. In 2008, only half those entitled to vote actually cast their ballots – a participation rate well beneath that of African Americans (65%) and whites (66%).

The turnout of Hispanics in November could be even lower, as Census Bureau data suggests that the number of Latinos who are registered to vote actually declined by 600,000 between 2008 and 2010. Pew suggests the slump could be explained by a tailing off of political interest following the exceptional enthusiasm engendered by Obama's first run for the White House four years ago.

It could also have something to do with the economic downturn. Many Hispanic families have been forced to move home because of foreclosures since the collapse of 2008, which in turn would have caused many of them to lose their electoral registration.

Looked another way, though, and the statistics spell enormous potential rewards for any politician or political party who manages to release the Latino genie from the bottle. If Hispanic Americans can be persuaded that it is worth their while to turn up on election day, then there is room for a massive mobilisation of new voters.

That is particularly the case in three vital swing states – Florida, which has more than 2 million eligible Hispanic voters, or 16% of the total; Colorado, with almost 500,000 (14%); and Nevada with 270,000 (15%). President Obama has been actively courting the Hispanic vote this year, with the introduction of a procedural change that allows young undocumented Latinos to apply for a two-year postponement of the threat of deportation.

On the other hand, there is a further weakening of Hispanic political power because families are concentrated in states that are not significant battlegrounds this election cycle. More than half of all potential Latino voters live in three states that are not in play this November – firmly Democratic California and New York, and firmly Republican Texas.

© Guardian News and Media 2012

[Latino family via Shutterstock]