By all means talk Trump, the political movement that won him the presidency and his populist rhetoric are a phenomenon worthy of discussion although there is little to say about his politics. And talk Clinton so long as you permit discussion about the corruption, the incompetence in office, and the way she rigged the primary to steal the nomination from Bernie Sanders. And talk Obama, his warmongering, Islamophilia, racism and love of terrorists (as expressed through his policy of funding ISIS and Al Nusra.)
Talk about how the USA might have been different under President Sanders.
Talk about Bush and Co. and Saddam Hussein’s non existent weapons of mass destruction, or about whether it might have been better to leave Saddam in office than plunge Iraq into the chaos its people have endured since the admittedly unpleasant regime fell. And mention that in deciding to bring down the regime, the Bush administration failed to consider what might replace it, given that there was no opposition movement in Iraq.
Talk Russia and how Putin is a dictator in all but name, but has turned that vast nation around since coming to power and delivered prosperity and a degree of freedom to people who for hundreds of years had known only oppression and deprivation, fist under the Czars and then under the Marxist tyranny of the Soviet Union.
Teachers, Republican or Democrat must leave their politics at home and if leading a discussion on politics, must be completely unbiased and able to ensure all opinions, no matter how naive, are given equal treatment.