Rory Hearne (45) a Maynooth University academic was a founding member of the People Before Profit Alliance in 2005, and ran unsuccessfully as their candidate in Dublin South-East in 2007.
He also briefly joined the Labour Party before resigning in 2011 in protest at their decision to go into government with Fine Gael.
In 2016 and 2020, he ran unsuccessfully for the Seanad as an Independent.
Mr Hearne joined the Social Democrats in 2024 and ran, unsuccessfully again, in European elections for the Midland-North-West constituency.
With party colleague Roisín Shortall stepping down after 32 years a TD in Dublin North West, his chances of election were certainly better here and he ended up first over the line. His own national profile as a media commentator, particularly on housing and homelessness is likely to have boosted his vote.
Hearne is associate professor in social policy Maynooth University and is married with four children.