The Libertarian Party has lost a legal case designed to get its candidate into the final US presidential TV debate.
Michael Badnarik was arrested while pushing his demand to debate
Lawyers said it was unfair to let only George W Bush and John Kerry in the contest that will be seen by millions.
They said the Democrat and Republican candidates were enjoying privileges denied to Libertarian Michael Badnarik.
But a judge declined to issue an injunction to block the debate or put Mr Badnarik on the stage, deciding the Libertarian case was not strong enough.
Maricopa County Superior Court Judge Pendleton Gaines, however, did leave the way open for the Libertarian Party to sue the Commission on Presidential Debates, which organises the TV contests, as well as the two major parties.
The Libertarian Party argued that Arizona State University was effectively giving huge donations to the Republican and Democratic parties by only allowing their candidates to take part in the debate on the university campus.
The rules for the debate were set by the Commission on Presidential Debates, which said only candidates who had shown they were supported by 15% of the electorate could take part.
But the Libertarians argued that Arizona State University was liable as it was donating about $2m in resources to the debate thereby breaking laws on contributing to political campaigns.
Judge Gaines rejected the claims, and said the debate would have civic and educational value. He also questioned why the Libertarians had waited so long to file the claim.
Mr Badnarik was arrested in St Louis on the night of the second presidential debate last Friday.
He tried to cross a police line to serve the Commission on Presidential Debates with a court order requiring a representative to appear at the case.
The Green Party presidential candidate, David Cobb, was also arrested as he tried to get access to the debate.