In a freewheeling speech about immigration, public debate and "cancel culture", he suggested the former Hawthorn coaching duo had been treated unfairly after being accused of racism towards Indigenous players.
Clarkson is now at North Melbourne and Fagan coaches Brisbane. Both men have been stood down pending the results of an investigation.
Mr Tehan, who served as trade minister in the former coalition government and is now the opposition spokesman on immigration, waded into the controversy during a speech to the National Press Club.
"What does it say of Australian values when the court of public opinion can rush to find someone guilty based on an accusation, without the presumption of innocence, a right to respond, or even the opportunity to test the allegation?" Mr Tehan said on Tuesday.
He also delved into the controversy surrounding Mr Thorburn, who resigned just a day after being appointed Bombers CEO due to his role as chair of a church with divisive views about abortion and homosexuality.
Essendon told Mr Thorburn he couldn't be at the club while remaining in his role at his church.
"We should be able to debate serious issues in a serious way … but when it comes to defending the values that make Australia great and that are central to being a good citizen, good people are cowed into silence," Mr Tehan said.
He attempted to link the Essendon controversy to bullying allegations levelled against Greens senator Lidia Thorpe.
"Why is Andrew Thorburn hounded from his job because of the actions of someone else in his church yet Adam Bandt gets a free pass when his colleague Lidia Thorpe bullies a respected Indigenous elder, directs disgraceful abuse towards a Liberal senator and celebrates Old Parliament House being set on fire?" he said.
