AAP's triumph over the national capital

After receiving a drubbing in 2014 Lok Sabha polls, failing to win a single seat in Delhi, the party surprised its detractors by winning 67 seats in the 70-member Delhi Assembly polls.
The AAP win halted BJP's victory march, after the saffron party won successive elections in Maharashtra, Haryana, Jharkhand and Jammu and Kashmir. But soon, differences within the AAP, which had been simmering for sometime, came to the fore.
The storm that hit AAP

In a National Executive meeting held at a resort in Kapashera in Outer Delhi, Kejriwal camp attacked its founder members Prashant Bhushan and Yogendra Yadav for alleged 'anti-party' activities. The camp also accused the duo of working to ensure AAP's defeat in the polls, a charge denied by the two.
The two leaders were against selection of candidates and the 'growing personality cult' of Kejriwal. Incidentally, Bhushan and Yadav were the founder members of the party and part of the all-powerful Political Affairs Committee and National Executive.
The two sides made a brief, but unsuccessful attempt to bury their hatchets. Kejriwal had insisted on the duo's ouster from the PAC and National Executive. However, both the sides failed to meet a common ground.
The duo was removed form the party's PAC. What followed was a controversial National Council meeting held on March 28, where Bhushan and Yadav accused Kejriwal supporters of man-handling their supporters and were expelled from the National Executive.
The duo, along with their supporters Ajit Jha and Anand Kumar were eventually sacked in April. This was followed by a series of expulsions and resignations of several members, many of them joining Swaraj Abhiyan, the group founded by Bhushan and Yadav.

Affair of sacking ministers began
Several National Executive like Mayank Gandhi, Christina Samy quit from their posts while others like Rakesh Sinha, Vishal Lathe were suspended. The party also sacked its Lokpal Admiral (retd) L Ramdas after he raised questions on 'one-party-one post' and whether should Kejriwal head both the government and the party.
Owing to the internal rebellion, AAP also suspended two of its MPs Dharamvira Gandhi and Harinder Singh Khalsa for 'anti-party' activities. While Gandhi had protested against the way Bhushan and Yadav were expelled from the party, he along with Khalsa were unhappy over the appointment of 13 observers in Lok Sabha constituencies in Punjab without seeking their opinion.
AAP's Timarpur MLA Pankaj Pushkar from Delhi also rebelled and openly aligned with Bhushan and Yadav's Swaraj Abhiyan. The AAP government in Delhi also saw its constant clashes with the Modi-led government. On the governmental level, it  accused the Centre for not allowing smooth functioning of its dispensation.

Centre, AAP, Delhi Police and the CBI raid

At the political level, it attacked the BJP for allegedly using Delhi Police against its MLAs and workers. However, a major flash point reached when CBI raided Chief Minister's Secretariat which prompted Kejriwal to call PM Modi a 'cowardice' and  'psychopath' and using investigating agencies against Opposition.

Kejriwal alleged that the raid was an attempt to find out the details of alleged irregularities against Union Finance Minister and senior BJP leader Arun Jaitley.
Six AAP MLAs were booked under various cases, for which the party accused the Delhi Police for working at the behest of Centre. This included serving Law Minister Jitendra Singh Tomar, who was eventually sacked from the Cabinet.
Kejriwal's ganging up with his Bihar counterpart Nitish Kumar and West Bengal Chief Minister Mamata Banerjee was seen as an attempt to form a strong anti-Modi camp. Although the party has no MP in Rajya Sabha, the MPs from the JDU and TMC lend their voice to AAP in the Upper House.