Treatment Purchase Scheme has quietly begun to do the business
"Out of left field" is figurative, rather than political, since the idea actually came from the Progressive Democrats, whose field tends to be on the right, rather than the left. Fianna Fáil believed it should have been shoved right back into whichever field it came from. And concealed under the nearest cow-pat. It exemplified an aspect of the PDs the Soldiers of Destiny will never get used to: the ruthless separateness of the smaller party.
Fianna Fáil thinks if you go to bed with a political partner, once the earth stops moving, they should act like you and think like you. Whenever Fianna Fáil goes to bed with another party, it grows to genuinely like, trust, and feel comity with them and convinces itself that it's just an oddity of circumstance that keeps the smaller group from realising they really and truly belong in the Fianna Fáil bed permanently. Until the smaller party comes to that realisation, Fianna Fáil expects them to at least show solidarity.