How much will it matter who John Kerry's running-mate is?

John Kerry, the Massachusetts Senator and Democratic Party challenger to President George W. Bush, telephoned me while I lived in Washington during the first half of this year… and trust him to call when I'd just ducked out!

Luckily my answering machine caught his message.

"If you want us to replace George Bush, press 1 and listen carefully. To show us how strongly you feel about sending George Bush back to Texas, please press 1 now."

At the time, speculation was rife about Kerry's choice for a Vice-Presidential running mate. A dozen or more names were bandied around, including a former NATO general, a number of state governors, various congressional luminaries -  even a prominent Republican.

Who knows, I thought, maybe he wanted to confound all the pundits and pick some obscure Australian? Press 1 to be Vice-President. You know - to illustrate his international credentials.

But then again, there is that whole Constitutional requirement for a President to be American born. What would happen if Kerry became the second JFK to fall victim to an assassin? This would create a messy succession.

He probably just wanted money.

Kerry recently made the long anticipated announcement of his running mate for the November election.  John Edwards, a Senate colleague from North Carolina, will square off on the "Veep" ballot against incumbent Dick Cheney.

Affable, smiling and youthful, Edwards looks the model of an American politician on the campaign trail. He came to prominence earlier this year in the Democratic primaries, running against Kerry for the party's presidential nomination. Adopting a populist style, he littered his speeches with the sort of lofty rhetoric expected from US leaders.

Having served just one five-year term in the Senate, he surprised a few people with his apparent hurry for the White House. While his campaign stuttered initially because he was unable to match the all-important fundraising skills of Kerry or the agitator Howard Dean, Edwards managed to hang in there in the race and emerge a surprise runner-up to Kerry.

This was largely credited to his positive style. He refused to engage in personal slanging matches with the other candidates, instead focusing on his key, albeit superficial message.

The country is unfairly divided, Edwards claimed. Over and over he pointed toward "two Americas"; one wealthy and coddled by the Bush administration, the other comprising the majority of "ordinary folks" struggling in the mainstream. He spoke often about his father, a poor mill-worker, as the example of the forgotten middle-classes.

This message, repeated in town hall meetings from Iowa to Tennessee and all other states besides, gave Edwards a local prominence that masked his relative political inexperience. In March, after Edwards conceded the Presidential nomination to Kerry, one Washington Post columnist urged Democrats to "steal this speech" in their effort to draw back disaffected voters from independent candidates. But it was the personal delivery with Edwards' strong Southern inflection, rather than substance, that counted most.

Those who knew Edwards pointed to his background as a trial-lawyer, where he possessed a famed ability to charm a court room jury. There he made his millions (presumably giving him plenty of experience of both "Americas") before running for the Senate.

Edwards, the political cleanskin, will make a good contrast with Cheney, the consummate Washington insider. Cheney is accused of secret dealings, rank partisanship and assorted conflicts of interest, including one with a sitting justice of the Supreme Court. Edwards's easy-going campaign style will challenge Cheney, who often seems uncomfortable with public engagements.

Yet despite his success, Edwards was by no means guaranteed a place with Kerry on the Democratic ticket.

For months, many observers salivated about the prospect that outspoken Republican Senator John McCain might join Kerry, a friend and fellow Vietnam veteran, in a bipartisan bid for the White House. Party discipline in the US is far less rigid than in Australia. McCain is an established critic of Bush's radical agenda in foreign policy, frequently taking on members of the administration in very public stoushes. A Kerry-McCain team would have appealed to so-called moderate Democrats and Republicans alike, regarded as key swinging voters in the election.

Refusing to follow the script, McCain barely even feigned interest. Recalling how he spent several years in a North Vietnam prison camp, he memorably described the Vice-President's role as being kept in the dark and fed only on scraps.

This is because ultimately the American people will not vote according to their favourite Vice-Presidential candidate. This mini-contest will be interesting to political enthusiasts, with Edwards pushing the Democrat's domestic policy while Cheney continues to muckrake and attack.

But the real choice remains whether to vote for John Kerry and send George Bush back to Texas.