India, Jan. 13 -- It is back to the 1960s in Mumbai, going by the poll rhetoric of the Thackeray cousins. Politically cornered and weakened by splits, the Shiv Sena (UBT) of Uddhav Thackeray and the Maharashtra Navnirman Sena of Raj Thackeray have fallen back on Marathi identity concerns to stay in the race to retain the Brihanmumbai Municipal Corporation (BMC). The pre-split Shiv Sena was an ethusiastic espouser of the Hindutva agenda - and this worked electorally in Mumbai, which has seen a rise in migration from northern India. But with the Thackerays falling out with the BJP, they have sought to set the clock back, claiming that "this (the election) was the final battle for Mumbai and Marathi manoos (people)". Their shrill campaign ha...