Explanation:

At the Nagpur session in December 1920, some crucial changes were made in the organization of the Congress, so that it becomes a real political party. These changes were actually mooted by Gandhi, but they confused Jinnah and Jinnah left the party, a beginning of the division that later would make him Qaide-i-azam of Pakistan.
Important Changes in Congress Earlier the object of the Congress was to attain self Government by constitutional and legal means. The new aim of congress was attainment of Swaraj by legitimate and peaceful means. Here, was confusion. Jinnah and Madan Mohan Malviya were confused whether this object of Swaraj is to make any connection with the British Empire or any other way out. Jinnah was still not convinced because the objective was still not clear. Thus Jinnah said adieu to the Congress and left it after his association for 15 years with the party. A 4 anna membership was launched so that more and more poor people could join the Congress A hierarchy of village, taluka and district level committees was to be created so that Congress reaches to the Grassroots. Reorganization of the Provincial Congress Committees so that now they would be organized on linguistic basis. The idea was to bring it close to the masses by using the vernacular languages. The numbers of delegates were to be fixed in proportion to the population. The above changes in Nagpur session paid the party dividends when it walked away with independence in 1947 and elections were held later on. Congress is still the largest political party in the country, though, now it is not of the same character and value