Tenth Circuit Judge Neil Gorsuch, President Trump’s choice for the U.S. Supreme Court, has a sparse but good record in cases involving independent candidates and minor parties. In January 2014 he was part of a 3-judge panel that struck down a Colorado campaign finance law that discriminated against supporters of independent and minor party candidates. Although he did not write the decision in Riddle v Hickenlooper, 742 F 3d 922, he agreed with his two colleages, Judges Bobby Baldock and Robert Bacharach, that the law was unconstitutional. He was so interested in the case that he wrote his own concurrence.
Here is a link to the entire decision. The lower court had upheld the Colorado discrimination on the grounds that Democrats and Republicans “need” more campaign contributions than minor party and independent candidates do.