The AAP's dramatic rise and the comeback of Lalu Prasad and Nitish Kumar in Bihar marked the first full year of Prime Minister Narendra Modi, who analysts say is still going strong though his earlier sheen has worn off.
For a politician who seemed to be at the peak of his popularity when 2015 dawned, having led the BJP to a historic win in the general election and later in Maharashtra, Jharkhand and Jammu and Kashmir, Modi suffered the maiden electoral defeat of his career in Delhi in February.
It was a personal blow for Modi because the Aam Aadmi Party (AAP), which swept away the BJP in assembly polls, was led by Arvind Kejriwal, who Modi crushed in the Lok Sabha election in Varanasi in May 2014.
Nine months later, Modi suffered the second major jolt -- and of a far serious nature -- when his personalized campaign failed to help the BJP to defeat JD-U leader Nitish Kumar and RJD chief Lalu Prasad. If the BJP won just three of 70 seats in Delhi, it got 53 of 243 seats in Bihar.
The Bihar outcome led to open dissidence in the BJP, whose four senior leaders - L.K. Advani included - publicly called for a thorough review of the defeat. The statement was seen as an attack on Modi and BJP president Amit Shah, his Man Friday.
Amid the electoral reverses, the opposition, particularly the Congress, crushed in 2014, fired salvos after salvos. Charges of corruption and wrongdoing enveloped External Affairs Minister Sushma Swaraj and the chief ministers of Madhya Pradesh and Rajasthan, Shivraj Singh Chouhan and Vasundhara Raje.
Sushma Swaraj and Raje were linked to controversial ex-IPL chief Lalit Modi while Chouhan was blamed for a recruitment scandal which also led to some reported 50 deaths. The CBI was asked to probe the scam and deaths.
Although the Congress faced a bleak year, the exception being Bihar where it was a junior partner to the JD-U and the RJD, its leader Rahul Gandhi forced the government to go on the back foot on its land bill that he said would take land away from farmers for industrialists.
Rahul Gandhi also showed more assertion and articulation after a 50-day sabbatical. No one seemed to know for sure where he was during this time.
The Congress crippled both the monsoon and winter sessions of parliament on a range of issues from "intolerance" to alleged corruption in Delhi's cricket body DDCA.
Just ahead of the Bihar election, the brutal killing of a Muslim man in Uttar Pradesh on rumours that he ate beef led to unprecedented surrender of awards by leading writers and artistes, embarrassing the government.
Despite the BJP's reverses, Modi's personal popularity remained high. He continued to tour numerous countries, and ended 2015 with a historic visit to Pakistan that earned him widespread praise.
And the BJP became a part of the government in Jammu and Kashmir, the country's only Muslim-majority state, for the first time, as a junior ally to the PDP.
AIADMK leader J. Jayalalithaa returned as Tamil Nadu's chief minister after being acquitted in a case of holding disproportionate assets, which had forced her to give up the job.
Congress president Sonia Gandhi and vice president Rahul Gandhi faced legal trouble in a case involving the now shut National Herald newspaper - on a complaint pursued by BJP leader Subramanian Swamy.
The BJP also faced unprecedented trouble in Modi's home state Gujarat, with a young Hardik Patel bringing thousands of Patels on the streets for job quotas. He was accused of sedition but the BJP suffered huge reverses in later civic body elections.
The unending BJP-opposition frictions buried the Goods and Services Tax bill, which could not be passed in parliament.
The BJP had some reasons to cheer. It made gains in local body elections in Kerala - where it has never won an assembly seat - and bagged two assembly seats in Manipur.
Even the end of 2015 saw fireworks.
The CBI raided in December the Delhi Secretariat, targeting a senior official aide to Chief Minister Kejriwal charged with corruption. But the AAP leader alleged his office was searched for what he said was a file linking corruption in the Delhi and District Cricket Association (DDCA) to Finance Minister Arun Jaitley.
A furious Jaitley - known to be close to Modi - filed a defamation case against Kejriwal. And the BJP suspended its MP Kirti Azad, who had been campaigning on the issue for long, leading to more disquiet among party veterans uncomfortable with the working style of Modi and Amit Shah.
(Prashant Sood can be contacted at prashant.s@ians.in and Brajendra Nath Singh can be contacted at brajendra.n@ians.in)
