"There is a hereditary class of brahmanas called the smarta-brahmanas, however, who are of the opinion that even if such persons who are chanting the holy name of the Lord are accepted as purified, they still have to perform the Vedic rites or await their next birth in a family of brahmanas so that they can perform the Vedic rituals. But actually that is not the case. Such a man does not need to wait for the next birth to become purified. He is at once purified. It is understood that he has already performed all sorts of rites. It is the so-called brahmanas who actually have to undergo different kinds of austerities before reaching that point of purification. There are many other Vedic performances which are not described here. All such Vedic rituals have been already performed by the chanters of the holy name."
Srimad-Bhagavatam 3:33:7 Purport
"Devotees who actually engage in devotional service with faith and love are inspired by the Supreme Personality of Godhead. Vaisnavas are never concerned with ritualistic smarta-brahmanas. Srila Sanatana Gosvami has therefore compiled Hari-bhakti-vilasa to guide the Vaisnavas, who never follow the smarta-viddhi. Although the Supreme Lord is situated in the core of everyone's heart, unless one is a Vaisnava, unless one is engaged in devotional service, one does not get sound advice by which to return home, back to Godhead."
Srimad-Bhagavatam 8:20:14 Purport
"Recently, when we established a large Krsna-Balarama temple in Vrndavana, we were obliged to have Vedic ceremonies enacted by brahmanas because the inhabitants of Vrndavana, especially the smarta-brahmanas, would not accept Europeans and Americans as bona fide brahmanas. Thus we had to engage brahmanas to perform costly yajnas. In spite of these yajnas, the members of our Society performed sankirtana loudly with mrdangas, and I considered the sankirtana more important than the Vedic ritualistic ceremonies. Both the ceremonies and the sankirtana were going on simultaneously. The ceremonies were meant for persons interested in Vedic rituals for elevation to heavenly planets (jadi-krta-matir madhu-puspitayam), whereas the sankirtana was meant for pure devotees interested in pleasing the Supreme Personality of Godhead. We would simply have performed sankirtana, but then the inhabitants of Vrndavana would not have taken the installation ceremony seriously. As explained here, the Vedic performances are meant for those whose intelligence has been dulled by the flowery language of the Vedas, which describe fruitive activities intended to elevate one to the higher planets."
Srimad-Bhagavatam 6:3:25 Purport
"Sarvabhauma Bhattacarya was previously a smarta-brahmana--that is, one who strictly follows the Vedic principles on the mundane platform. On the mundane platform one cannot believe that prasada is transcendental, that Govinda is the original form of the Supreme Personality of Godhead, or that a Vaisnava is a liberated person. These transcendental considerations are out of the ordinary Vedic scholar's jurisdiction. Most Vedic scholars are called Vedantists. These so-called followers of Vedanta philosophy consider the Absolute Truth to be impersonal. They also believe that a person born in a particular caste cannot change his caste until he dies and takes rebirth. The smarta-brahmanas also reject the fact that maha-prasada (food offered to the Deity) is transcendental and materially uncontaminated."
Caitanya-caritamrta, Madyam lila 12:18
"Mayavadi sannyasis consider themselves Brahman, and they superficially speak of themselves as Narayana. The monistic disciples of the Mayavada school (known as smarta-brahmanas) are generally householder brahmanas who accept the Mayavadi sannyasis as Narayana incarnate; therefore they offer their obeisances to them. Sri Caitanya Mahaprabhu immediately protested this unauthorized system, specifically mentioning that a sannyasi (cit-kana jiva) is nothing but a fragmental portion of the Supreme. In other words, he is nothing more than an ordinary living being. He is never Narayana, just as a molecular portion of sunshine is never the sun itself. The living entity is nothing but a fragmental part of the Absolute Truth; therefore at no stage of perfection can a living entity become the Supreme Personality of Godhead. This Mayavada viewpoint is always condemned by the Vaisnava school. Sri Caitanya Mahaprabhu Himself protested this philosophy. When the Mayavadis accept sannyasa and consider themselves Narayana, they become so puffed up that they do not even enter the temple of Narayana to offer respects, for they falsely think themselves Narayana Himself. Although Mayavadi sannyasis may offer respects to other sannyasis and address them as Narayana, they do not go to a Narayana temple and offer respects. These Mayavadi sannyasis are always condemned and are described as demons. The Vedas clearly state that living entities are subordinate parts and parcels of the supreme. Eko bahunam yo vidadhati kaman: the Supreme Being, Krsna, maintains all living entities."
Caitanya-caritamrta, Madyam lila 18:11
"There is a difference between the smarta process and the gosvami process. According to the smarta process, one cannot be accepted as a brahmana unless he is born in a brahmana family. According to the gosvami process, the Hari-bhakti-vilasa and the Narada-pancaratra, anyone can be a brahmana if he is properly initiated by a bona fide spiritual master."
Caitanya-caritamrta, Madyam lila 23:10
"There are two processes of Vedic understanding, Smarta-vicara and Gosvami-vicara. According to Smarta-vicara, unless a person born in a low-grade family takes another birth, he cannot be eligible to become a brahmana. But according to Gosvami-vicara, if he's properly initiated by a bona fide Vaisnava, then he becomes more than a brahmana. Svadyo 'pi sadyah. Immediately he becomes eligible to perform sacrifices. so the problem is that at the present moment we are not taking care... I mean that our Indian brahmanas, those who are spiritual leaders, they are not actually taking care of the fallen souls. But in the Bhagavad-gita it is sanctioned, it is said clearly: mam hi partha vyapasritya ye 'pi syuh papa-yonayah. Any person born of low-grade family, papa-yoni, striyo vaisyas tatha sudras te 'pi yanti param gatim... So it is the duty of the elevated person, brahmanas and Vaisnavas, to take charge of this business."
Srila Prabhupada Lecture on Nectar of Devotion, 11-06-72, Vrindaban
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.