Creating friction. Nazri's latest antics, here, can spark a crisis between Tun Dr Mahathir Mohamad and the Prime Minister. So far, their relations have been cordial. If Dr M thinks that Nazri was put up to it and Najib Razak chooses to keep quiet, the situation can be like what we saw during Pak Lah's tortured reign, when the PM was seen as using his machais to demonize Dr M, which forced Dr M to attack Pak Lah.
If Dr M and Najib are at loggerheads, it won't be good for Umno and BN. And if Dr M starts whacking Najib the way he was whacking Pak Lah, it can't be good for the current Prime Minister.
Already, pro-Umno bloggers have called for Nazri's sacking from the party. Read Nazri Aziz wajar dipecat and Another turncoat: Just watch this caveman!
Updates: Syed Imran thinks Mahathir and Nazri dua kali lima
Jebat Must Die's Nazri Battling Against His Own Intelligence (and he won!)