The response to this is given from several angles:
First: This is not the position of Ahl al-Sunnah wa al-Jamā‘a. Their doctrine is not that merely because one person pledges allegiance to a man of Quraysh (1), the pledge of allegiance to him becomes validly established and all (2) people are obliged to obey him. Although some kalām theologians have said this, it is not the position of the imams of Ahl al-Sunnah (3) wa al-Jamā‘a. Rather, Umar ibn al-Khattāb [may Allah be pleased with him] (4) said: “Whoever pledges allegiance to a man without (5) consulting the Muslims, neither he nor the man to whom he pledged allegiance should be given allegiance, lest they both be killed.” This hadith was narrated by al-Bukhārī and will be quoted in full later, Allah Most High willing.] (6).
(1) “And merely because he pledges allegiance to a man of Quraysh.”
(2) “All” is omitted from (A) and (B).
(3) (N) and (M) read: “the position of Ahl al-Sunnah”; (W) reads: “the position of the imams of the Sunnah.”
(4) “May Allah be pleased with him” is an addition in (A) and (B).
(5) (N), (M), and (W) read: ʿan ghayri (“without”).
(6) The passage between square brackets is an addition in (A) and (B). This is part of a lengthy report narrated by al-Bukhārī from Ibn ʿAbbās—may Allah be pleased with him and his father—in his Sahīh, 8:168–170, Book of Those Who Wage War from among the Disbelievers and Apostates, chapter “Stoning a Pregnant Woman Guilty of Adultery.” It begins: “Ibn ʿAbbās said: I used to teach several men among the Muhājirūn (Emigrants) to recite, including ʿAbd al-Rahmān ibn ʿAwf. While I was at his home, he was with ʿUmar ibn al-Khattāb during the last pilgrimage ʿUmar performed…” Ibn al-Athīr said in al-Nihāya fī Gharīb al-Hadīth wa al-Athar, 3:156: “Al-taghirra (exposure to peril) is the verbal noun of gharartuhu, meaning, ‘I exposed him to danger.’ It is derived from al-taghrīr, just as al-taʿilla is derived from al-taʿlīl. The hadith means that a pledge of allegiance should properly proceed from consultation and agreement. If two men act unilaterally, apart from the community, and one pledges allegiance to the other, they are thereby colluding to cause a schism and cast aside the community. If a pledge of allegiance is concluded for anyone, its recipient should be neither of them; both should be excluded from the group from among whom the imam is chosen by agreement. For if allegiance were concluded for one of them after he had committed that reprehensible deed—which angered the community because he treated them lightly and dispensed with their opinion—there would be no assurance that the two would not be killed.” The report from Ibn ʿAbbās—may Allah be pleased with him and his father—also appears in al-Musnad (al-Maʿārif ed.), 1:323–327.