There were many reasons for NDA defeat in Parliament election of 2009, some of them are mentioned which were visible and strong:-
1) Shri Varun Speech in UP which made Muslims Voters went away as they were coming slowly near to NDA.
2) Ram sena misbehavior with female which led massive damage mainly in Karnataka and urban area of India for BJP.
3) Shri Chiranjivi party cut votes for TDP.
4) Smt. Jaylalita was not aggressive for Tamil's Cause in Sri Lanka.
5) Smt. Vasundhara Raje was not motivated well after defeat of assembly poll in Rajasthan so her approach was very low towards Parliament election.
6) Anti-accumbency for Punjab CM as agricultural problem, division of Sikh community, and as Sikh Mr.Manmohan Singh was projected UPA PM.
7) Shri Advaniji had given much stress on PM Manmohan Singh weakness attached to personal comment.
8) Shri Narendra Modi started dismantling Temples to attract Muslims Voters in Gujarat and India but failed. He should know that no one likes destruction and that also of religious places! This is called low mind approach.
9) At senior levels in BJP motivation were sacking like fevers (Up-down).
10) If BJD declared disassociation from BJP, Orissa BJP should not have separated, although giving reason that Politics at Center and Politics at States are different and made for different cause, one is attached to Entire country affairs and state is limited to state affairs only.
11) BJP does not have good Poll Managers after Late Shri Mahajan.
12) BJP does not have good class of Socio-Political advisers.
13) BJP Spokes person must be well educated, good communicator, must have sympathy for other religions, he must have good accent of Hindi and English, Spokes person must be divided in four regions and they must know Good English and other four side languages.
14) Smt.Uma was more or less accepted by BJP which created damage in MP, a failed person is not accepted by Society and that also very soon, as MP assembly poll was held recently.
Proper workout must be there for assembly election in Bihar otherwise voters may go hey-way and what happend in 2009 parliament election, can happen in Bihar in assembly election of 2010.