DEMOCRATIC Party hopefuls for the US presidency look set to get locked in battle of `paddywhackery' after former vice president Joe Biden proclaimed himself the only "real Irishman" running.
His remark after misunderstanding a reporter's question has been interpreted as a challenge to the more Irish-monikered candidates Beto O'Rourke, Tim Ryan and John Delaney.
Although hopeful Kristen Gillibrand could claim the female title through her maternal great-grandmother, Mimi.
While campaigning in South Carolina, Mr Biden told Irish-born Financial Times Washington editor Demetri Sevastopulo: "There's only one real Irishman running for president and its me."
Mr Biden has referenced his Irish heritage before.
Great-grandfather James Finnegan emigrated in 1850 from Co Louth as a child and all eight of his maternal great-great-grandparents were born in Ireland.
Meanwhile, two paternal great-grandparents were also born in Ireland.
Texas presidential hopeful Beto O'Rourke has Leitrim roots on his father's side and Carlow on his mother's.
On St Patrick's Day, the Republican party tweeted a mugshot of Mr O'Rourke embellished with a green leprechaun's hat and the words 'please drink responsibly'.
Matthew Dowd, former chief strategist for the Bush-Cheney 2004 Republican presidential campaign, tweeted in response: "As an Irishman this is deplorable. As an American it is unpatriotic. As a human it is racist."
Presidential candidates often stress their Irish links in order to appeal to the substantial cohort of Irish Catholic voters, particularly in the so called 'Rust Belt', and also New York City and parts of Massachusetts.
Supporters of the different candidates have now started debating their respective Irishness on Twitter.
