Why Do Gays Have "New Rights" and Do I Have to Bake Them a Cake?

Normally I use this blog to address issues specific to Wisconsin, but the recent Supreme Court decision in Obergefell v. Hodges justifies a departure from this practice.  In Obergefell v. Hodges the Supreme Court decided that the states cannot refuse to license a marriage between two people of the same gender, or refuse to recognize a marriage of two people of the same gender performed in another state.  The decision has given rise to commentary, some of it rather hysterical, suggesting that the Court created new Constitutional rights, and in so doing has infringed on the religious liberties of people who oppose gay marriage.  In this post I present a simple summary of the Constitutional basis of the Court's decision, and the Constitutional reasons why no one's religious liberties are in danger.
I. The Fourteenth Amendment Prohibits States from Violating Fundamental Rights.
The Supreme Court based its decision on Section 1 of the Fourteenth Amendment of the Constitution, which provides:
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside. No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any state deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws. 
Before the Fourteenth Amendment was added to the Constitution, there was some debate as to whether the Constitution protected citizens from state violations of rights, or only from federal violations.  The Fourteenth Amendment established that citizens are protected from both state and federal interference with fundamental rights.
II. The Court's Decision is Based on the Well-Established Fundamental Right to Marriage.
For the Fourteenth Amendment to apply, there must be a fundamental right at stake.  Several Supreme Court decisions have previously established that the right to marry is a fundamental right.  The lengthy case citations are in the decision. There really isn't much dispute over this point.
III. Gay Citizens are Entitled to Equal Protection of the Laws.
The Court concluded that the states that barred gay marriage were depriving gay couples of the fundamental right of marriage, thereby treating gay couples differently, not equally. There really wasn't any factual dispute; The issue was whether gays are entitled to equal protection.  The states opposing gay marriage argued that they aren't.  But previous Supreme Court cases have struck down laws that treated men and women differently and people of different races differently for the purposes of marriage, finding violations of the equal protection clause.  The Court also cited cases holding that gay couples have the same rights to privacy as other couples.  The Court reached the conclusion that the equal protection clause applies as much to gay couples as straight couples, and therefore the states cannot deny them the fundamental right of marriage.
IV. You Don't Have to Bake the Gays a Cake.
One common misconception about "constitutional rights" is that once you have them, no one can violate them.  That is not true.  The Constitution only limits what the government can do.  The government (state or federal) cannot infringe on your free speech rights, but your neighbor can tell you to shut up. The government cannot treat you differently because you are black, but your co-worker can refuse to go to lunch with you because you are black.  The effect of Obergefell is that state and federal governments cannot treat gay people different from straight people for the purposes of marriage, but the case has no effect on how private citizens can treat each other.  Furthermore, the Court recognized that the free speech and freedom of religion provisions of the First Amendment absolutely protect the rights of clergy to refuse to marry a gay couple. The decision requires states to issue marriage licenses, but it does not require private citizens to perform the ceremonies or otherwise be involved in the event. Marriage has long been recognized as a fundamental right for male-female couples, yet clergy have maintained the right to refuse to marry couples whom they determine are not abiding by the faith.
The entire decision is available here: http://www.supremecourt.gov/opinions/14pdf/14-556_3204.pdf

Do Workers in a Non- Right-to-Work States Have to Join Unions?

No.  Even before right-to-work legislation, Wisconsin workers in unionized workplaces did not have to join unions, although they could be required to pay a portion of union dues to compensate the union for representational services such as negotiating collective bargaining agreements, challenging employee discipline and termination, and arbitrating disputes over wages and benefits.

Under federal labor law, unions have a duty to represent not only their members, but everyone in a bargaining unit.  A bargaining unit consists of non-supervisory employees who are similarly situated in the workplace.  In a factory, for example, the bargaining unit is usually every non-supervisory employee working in production. Since unions have to represent everyone in the bargaining unit, they historically required everyone to be in the union and pay dues.  Throughout the decades there have been many legal challenges to this practice, claiming that it violated employees' rights of association to be required to join a union, and violated their rights of free speech to be required to contribute funds for political action.  A series of Supreme Court cases, culminating in Communication Workers of America v. Beck, 487 U.S. 735 in 1988, established that: 1) Employees cannot be required to join a union in a unionized workplace; 2) Employees can be required to pay an "agency fee" to the union that includes only the portion of dues used to represent the bargaining unit (negotiating collective bargaining agreements, challenging employee discipline and termination, and arbitrating disputes over wages and benefits); 3) Employees have a right to challenge the amount of an agency fee and obtain an explanation of how agency fees are spent.  As a result, in recent decades unions have generally endeavored to allocate the vast majority of dues collected to the cost of representing employees, and have funded political action by soliciting members to voluntarily contribute to union political action committees (PACs).  

When right to work laws are adopted, unions still have to represent the entire bargaining unit, but employees can choose to pay no dues, thus obtaining the union's representational services at no cost.