The Atlantic Monthly has this article on whether a new presidential candidate still has time to enter the presidential race. The article discusses the possible interaction of anti-Trump Republicans with the Constitution and Libertarian Parties.
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Here is a link provided by Politico for Wisconsin presidential primary election returns.
On April 5, a state trial court in Columbus, Ohio, heard testimony in Libertarian Party of Ohio v Husted, 16-cv-554. Bob Fitrakis of the Ohio Green Party, Kevin Knedler of the Libertarian Party, and Bob Bridges of the Libertarian Party, all testified. The lawsuit argues that the 2013 ballot access law violates the State Constitution, because that Constitution seems to say that all parties must nominate by primary, yet the 2013 law says new parties don’t nominate by primary. The State argued that the Ohio Constitutional provision mandating primaries for all parties can’t really be enforced by a lawsuit.
Kentucky requires candidates for state office who are running outside the qualified parties to file a declaration of candidacy by April 1. This year, only one minor party candidate, and three independent candidates, filed for the state legislature (which is the only state office up in 2016). The declaration of candidacy filing requirement does not apply to federal office. See this story. The only minor party candidate is a Libertarian.
Last time Kentucky held legislative elections, in 2014, there were no minor party candidates, and only two independent candidates.
Petitions for these candidates are not due until August, and require 100 signatures.
Saskatchewan held a provincial election on April 4, 2016. All the seats were won by either the Saskatchewan Party or the New Democratic Party. Six parties participated, but the Liberals only won 3.6% of the popular vote (even though it is the governing party in Canada’s national government), and the Progressive Conservatives only won 1.3% of the popular vote. See this wikipedia article about the election results.