Here's what Paddy Graber said about it:
It's almost impossible to give an Irish song without giving a history lesson along with it, so I'll start in right now. The song I'm going to sing next is called "Daniel O'Connell", and it's about a man who's a member of parliament, and he was known as "the great Liberator", God knows for why, for he had a voting record like Barry Goldwater. Actually he'd lived through the rebellion of 1798 and he'd seen the terrible things that had happened at that particular time to the Irish, and it just broke his heart, he didn't want to see anything like that happen again.
When the potato famine -- the Irish call it "the Great Starvation"; the English call it "the Potato Famine" -- when it came in 1845, 1846, he thought he would help the Irish people by voting to bring in a law which was known as "the repeal of the corn law" which in theory would make corn cheaper and the Irish people wouldn't need to die of starvation.
But because they couldn't own their own land, they had to rent land and they would grow crops and raise grain and cattle for export and from what little profit they could make from that, they were able to rent a small patch of land to raise potatoes. When the potatoes failed, of course, everybody died. And they were getting less for their grain so they couldn't even afford to rent the ground. [let alone buy corn at any price].
I guess the last temptation is the greatest (t)reason to do the wrong thing thing for the right reason. I guess he thought he was doing the best, but it certainly didn't work out that way.
He also invented [founded] the Bank of Ireland, and then of course he needed somewhere to invest the money, and he'd heard that Stephenson's Rocket had run from Manchester to Liverpool just a few years before, so he petitioned the High Lord Leftenant of Ireland, and he said in his petition, "If we only had a steam engine, it would be the making of future generations."
Well, the tinkers, the gypsies of Ireland, they heard this and they thought he was trying to make children by steam. This is where this particular song came from.