LONDON — Let’s look on the bright side: The spectacle of ireful Donald Trump supporters disrupting Shakespeare in the Park’s production of “Julius Caesar” and the subsequent tweetstorm of abuse directed at any company with Shakespeare in its name prove that plays retain the power to shock and enrage. Who said the theater is all anodyne, feel-good musicals?

I didn’t see the production that turned Julius Caesar into a Donald Trump look-alike, so I can’t comment on the accuracy of the impersonation or the violence against the president that some people believe it meant to incite. But there are a few things about the nature of Shakespearean drama in general — its subtle shifts in sympathy, the shocks it administers to our prejudices, its suspension of the drives to definitive political action — that obviously weren’t apparent to protesters.

The first of these is that a play, however incendiary its plot, is a very different thing from a political speech. A speech asks us to go out and do, or at least to go away and believe; a play by Shakespeare moves through time, measures action against motive and shows us consequence. We might enter the theater in rash spirits, but we leave it consumed by thought.