Tesla CEO Elon Musk rebuffed analyst Dan Ives' suggestion that Tesla's board establish guardrails for his political activism after he vowed to launch an America Party.

Mr. Musk’s involvement in politics and his financial support for the president’s campaign were 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.