Select all that apply Which of the following changes transformed the union certification process established by the National Labor Relations Act into a lengthy procedure? (Check all that apply.) Multiple select question. The Taft-Hartley Act required unions to establish majority support of employees before filing a petition for representation election. The Supreme Court required employers and unions to follow laboratory conditions standard during the election process. The Supreme Court and Section 8(c) of the Taft-Hartley Act explicitly permitted (noncoercive) employer participation in the certification process. The Supreme Court let employers to demand a secret ballot election, even if majority status confirmed by signed authorization cards is not in doubt