Private sector employees should enjoy the ability to organize themselves into union organizations to help provide for collective bargaining however it is the right of the individual to participate in a union and should not be proscribed as a requirement for employment unless the employer and union reach such an agreement by contract.
There is no basis or benefit to the government (the citizens; you and me) to recognize or negotiate with unions. Public employee enjoy some of the best wages, rights, benefits, and entitilements and should be enumerated in an employment contract with the individual and measured by their performance in direct comparison to an equal non-union contracted private sector position with no automatic increases, therefore Paul supports cancelling all union contracts on their expiration.
Where employees or groups of employees have or do establish a labor union these unions should be subject to laws similar to corporate anti-trust legislation to protect employers from not having choices in selecting their workforce. Unions should have to compete equally with individuals and other union organizations.
The following is paraphrased from the California Libertarian Platform:
Paul opposes government-mandated "right of access" to private property for purposes of union organizing, government-sponsored elections on establishing unions, and government-defined collective bargaining units. Paul supports an employer's and labor union's unrestricted right to exercise freedom of speech, consistent with private property rights, during a labor-organizing campaign.
Paul supports the right of persons to voluntarily establish, associate with, or not associate with labor unions. An employer has the right to recognize, or refuse to recognize, a union as the collective bargaining agent of some or all employees. Therefore, Paul opposes "right to work" laws because they prohibit employers from making voluntary contracts with unions. Likewise, unions have the right to organize secondary boycotts, if in so doing they do not violate individual rights or existing contractual agreements. Paul does not countenance individuals or associations, whether management or labor, making efforts to coerce collective-bargaining agreements.
Paul opposes government interference in contract negotiations, such as compulsory arbitration or imposing an obligation to negotiate. Paul calls for the repeal of all government laws and regulations interfering with employer-employee relationships such as the wage and hour laws, the Wagner Act, the Taft-Hartley Act, the California Occupational Safety and Health Act, and the California Agricultural Labor Act.
Paul favors replacement of the current workers' compensation system with a system of strict liability of employers for on-the-job physical injuries--a liability that can be modified or waived in contractual negotiations.
Paul repudiates the notion that the government should decree wages in accordance with its arbitrary political notions of comparable worth, and oppose all laws based on this concept.