Mahātmās are not interested within this material world. They are not under the influence of the external energy. Of course, nowadays it is... Sometimes politicians are called "mahātmā." But that is not the purpose of mahātmā. Mahātmā is not interested with politics or sociology or... They are all material things. Or philanthropy. They are interested with the Supreme: Brahman, Paramātmā and Bhagavān. Brahmeti paramātmeti bhagavān iti śabdyate (SB 1.2.11). They're interested. Especially mahātmā is he who is interested with the Supreme Personality of Godhead, Kṛṣṇa.
Every kṛṣṇa-bhakta, Kṛṣṇa conscious person, is mahātmā, real mahātmā. How it is? Kṛṣṇa says, mahātmānas tu māṁ pārtha daivīṁ prakṛtim āśritāḥ, bhajanty ananya-manasaḥ (BG 9.13). That is mahātmā. Mahātmā does not mean that if you dress yourself with a certain colored cloth and have some big hairs and beards, then you become mahātmā, no. The mahātmā is he... Who? Daivīṁ prakṛtim āśritāḥ: "He is not under the influence of this external energy." Daivī-prakṛti means... There are two prakṛtis, two natures: internal and external. Internal energy is spiritual energy, and external energy is material energy. So mahātmās, they are not under material energy.