Millions of Iranians are heading to the polls Friday in a snap election called after President Ebrahim Raisi died in a helicopter crash last month.

Facing severe headwinds, including a flagging economy, regional tensions and the potential re-election of Donald Trump, whose administration worked to isolate the Islamic Republic, Iran’s leadership is looking for a high turnout to endorse its hard-line agenda. 

Here is what to know about the tightly controlled election.

Why now?

The snap vote was…