Tommy is a hard working constituency politician, a reasonable Dail speaker and by most accounts, a decent fellow. Unfortunately for him, these are not sufficient qualities to be party leader. He lacks any visible support from any Labour big hitters. He lacks a national profile - but possibly this will-he-won't-he business was intended to raise one. Perhaps he thought that in a potentially divisive election between rival Labour factions he might - conceivably - have got in as a compromise candidate in a Jack Lynch, Jim Hacker sort of way. With no one else opposing Gilmore, that slim possibility was gone.
Since the election the point has been done to death but the lot of an opposition backbencher really is not a particularly happy one. He got my mother's minor matter sorted out with admirable efficiency but possibly this was the final straw for him.
'Screw this' he must have thought 'if I don't give this leadership lark a go, I'll be stuck dealing with this shite out of that shaggin' caravan 'til I retire'.