They said, corruption has become part of our DNA, it cannot be fought on the strength of principles alone
There is perceptible decline in petty corruption, government formation by nominees of corrupt corporates might buy them time but not a lot of it. But rest assured bribery is not going to be the same again.
The political class is too powerful, it cannot be challenged or made to change its ways by common folks through protests alone
AAP decimated the Congress in Delhi and scared BJP to the extent that despite being the largest party it refused to form the government. In Lok Sabha election, AAP changed the rules of the game,supreme leaders of national parties no longer had luxury of safe seats. Kumar Vishwas in Amethi and Arvind Kejriwal in Kashi rattled Rahul Gandhi and Narendra Modi, there is no ambiguity on who won the war of nerves.
Further, political power is defined as the ability to bring out desired behaviour in other actors without the use of force or coercion. From this perspective, the sudden decline in availing VIP privileges by politicians of all parties, taking up issues they were reluctant to take up earlier and ad hoc altering of well crafted political strategies to tackle the latest thrown by Aam Aadmi Party vindicates the stand that the seemingly invincible political class can be brought to its knees by a motley group of honest individuals.
In coalition era, taking the entire political establishment from leftists to right-wing parties, going alone is a recipe for disaster
AAP went without a bookish ideology, focusing more on the actual problems people were facing and working out plans on how to resolve them. Its pan-India presence today (within 2 years) fielding 450 candidates proves that you don't need a comprehensive political ideology to find following, you just need to understand people's problems, their aspirations and speak their language.
One way or the other a political party cannot exist without resorting to identity politics i.e. have backing of a community, caste or ethnic, linguist group that vote en block.
This is the biggest victory of AAP, unlike other parties it just did not address identity factors in political discourse. Rather it stuck to its agenda of cleansing the political landscape,so the basic needs of the people could be met. Do note, it did not, like the Sangh Parivar,demand or suggest abolition of sub-identities, AAP just did not address it.
Contesting election requires an obscene amount of money some of which have to be unaccounted for or black money
This is actually part of the vicious circle that has gripped Indian democracy like a snake and continues to squeeze it. If corporate donate money to the the tune of billions, they expect the party to dole out favors to them in return. During Delhi Vidhan Sabha election, AAP's entire poll expense was less than what is spent in a single rally of Narendra Modi.
Since AAP represents the common people, it sought funding from the very same people. Contrast this with the fact that traditional parties dole out cash to people to vote for them. As for overseas fund collection, it is the only party to have undergone High Court probe related to its overseas funding and has come out clean while both the Congress and the BJP have been found at fault. I suspect AAP has perhaps willingly de-prioritized fund collection.