Tonight’s third-party presidential debate has kicked off in Chicago. Sharing the stage at the Hilton Hotel are Libertarian Party nominee Gary Johnson, Green Party nominee Jill Stein, Constitution Party nominee Virgil Goode, and Justice Party nominee Rocky Anderson.

The Post’s Sean Sullivan, who is inside the debate hall, reports that Johnson received by far the loudest applause of the four candidates as they took the stage.

The first question from moderators Larry King and Christina Tobin is on the “top two” system of selecting candidates, which is used in some places including Washington State and will be on the ballot in Arizona this November. Most third-party candidates are opposed to the system, which they argue would spell the end of minor parties.

Anderson, a former Democrat, made one of the sharpest jabs at the major parties. He said at Tuesday’s debate that the system is an attempt by the Democratic and Republican parties to “further put their stranglehold on our democracy.” Johnson followed suit, taking aim at the major-party candidates as “tweedle dee and tweedle dumb.”