In recent weeks, a transatlantic row between Donald Trump and Pope Leo XIV has brought an old question back into sharp focus: what role, if any, should religion play in public life? For some, particularly among Trump’s supporters, religious leaders should refrain from commenting on political decisions altogether. For others, the Pope’s more measured response – that his role is not to intervene in partisan disputes but to speak to moral questions, including those raised by public policy – has struck a chord.