How did BJP manage to prevent adverse impact of PNB scam in Northeast?

The Congress or the Left Front failed to drive home the electoral advantage from the PNB scam and they must examine what could have gone wrong

On February 14, 2018, the Nirav Modi scam hit the nation. India’s second largest state-controlled lender, Punjab National Bank, informed the Bombay Stock Exchange that it had detected some “fraudulent and unauthorised transactions” pertaining to the letters of undertaking (LoU) it had issued at an estimated value of over Rs 114 billion. 

The amount involved was later revised to Rs 126 billion as more such transactions came to light. Companies owned by billionaire Nirav Modi,  a luxury diamond jewellery designer, and his uncle,