Musk has been able to play off Tesla's struggles for over a year now because the stock has been astonishingly resilient. Neither political gaffe nor falling deliveries has knocked Tesla off its upward trajectory, but Monday's selloff may be a sign of a changing sentiment.

Mr. Musk’s involvement in politics and his financial support for the president’s campaign was once seen by investors as a benefit to Tesla, fueling a steep rise in company shares after the election last year. That association has now turned into a liability. Tesla shares are down 40 percent from their peak in December.

Dan Ives, an analyst with Wedbush, wrote that Musk's continued push into politics is "exactly the opposite direction" investors want to see.