Are the new top dogs of Northern Ireland politics really so different? On the surface the answer is: “yes, of course”. Sinn Fein stands for a united Ireland while the Democratic Unionist Party (DUP) believes in the maintenance of the Union at all costs. Ideologically they are as different as chalk and cheese but, on other levels, they look like two peas in a pod.

The first striking similarity is the discipline which both parties display. Both the DUP and Sinn Fein brook no dissent in a way unparalleled anywhere else in the democratic world. Sinn Fein’s authoritarian streak goes back to its roots in the IRA where obedience is paramount. Whatever disagreements there are, they are always kept private. Sinn Fein members are nothing if not good soldiers. Dissenting voices are quickly shown the door – just ask John Kelly.

The DUP’s unity comes from one man, Ian Paisley, whose nickname, the Big Man, says it all. The party which he founded is very much his vehicle, his baby. He is indisputably leader for life. Anyone who doesn’t goes along with the Big Man has no future in the DUP.

This discipline, allied to a ferocious work ethic, has brought both great electoral dividends in recent years. Where the SDLP and UUP are seen as detached and lazy, the DUP and Sinn Fein are engaged and active. Their members are happy o do the legwork on the ground not just during elections but also in between. Solid constituency work explains a lot of their appeal.

Both parties have shown a remarkable ability to abandon failed policies, steal the clothes of their competitors and dress it all up as great strategy. In the last decade Sinn Fein has dumped the long war, joined a “partitionist” assembly, served in the government of Northern Ireland, accepted the principle of consent and decommissioned some of their weaponry. The message is obvious to anyone with half a brain – “we got it wrong”. Yet Sinn Fein has spun its capitulation to reality as somehow brave and principled. What is surprising is not that they tried to gloss over their failure but that so many people have believed them.

The DUP’s ideological shift, though less dramatic, is still significant. Gone is the old rhetoric against power sharing and “Dublin interference”. If we are to believe Peter Robinson, the DUP has no difficulty sharing power with the SDLP or talking to the Irish government. Their only problem is sharing a cabinet table with those whom they consider terrorists. In an appeal to moderate unionists the DUP says: “look, we’re not obstructionist bigots, we’re principled democrats”. In each case the strategy is the same: dump just enough ideology to win new voters without alienating your base.

There are even similarities in the mentality of the two parties. Both are insufferably self-righteous at all times. In their own minds they’re perfect, nothing is ever their fault, every one else is to blame. Who knows, maybe they actually believe this. Do Adams or Paisley ever suffer self-doubt? Does it ever occur to them that they are anything less than 100% right? I hope for the sake of their sanity they do.

Finally both parties have a common narrative. For so long the outsiders, they have finally overtaken their moderate rivals to become leaders of their communities. For decades Sinn Fein and the DUP have sniped at the SDLP and the UUP to “deliver” for their people. November’s election places the burden of leadership squarely on their shoulders. Gerry, Ian, it’s over to you