U.S. Supreme Court rulings from the 21st century include District of Columbia v. Heller in 2008, National Federation of Independent Business v. Sebelius in 2012 and Obergefell v. Hodges in 2015, according to USA Today. Each of these cases was decided by a 5-4 ratio.
District of Columbia v. Heller was brought to the Supreme Court by a special policeman in D.C. who was denied the right to register a handgun he wanted to keep at home, states Cornell University Law School. At the time, handguns for nonpolice use were effectively banned in D.C., as all firearms had to be registered, and handguns could not legally be registered. As a result of the Supreme Court case, the ban on handgun registration in D.C. was lifted.
National Federation of Independent Business v. Sebelius was a challenge to the Affordable Care Act's provision that all Americans must have health insurance coverage or pay a fee, according to Cornell University Law School. The National Federation of Independent Business and 26 states maintained that this provision was unconstitutional because they considered the fee to be a tax. The Supreme Court upheld this provision of the ACA, stating that the fee was a penalty, not a tax.
Obergefell v. Hodges was brought by several same-sex couples who were not allowed to marry in their states, reports the Huffington Post. The Supreme Court ruled that same-sex couples and straight couples have equal rights to marry, effectively making gay marriage legal in all 50 states.