In addition, technically the Secret Service can’t really stop him. The relationship between ex-Presidents and candidates and their protection details and actual Presidents is much different.
The Secret Service can request no outdoor events (which they’ve done) but they can’t make the decision.
The reason I asked for a source is that claim runs counter to statements by the Trump campaign:
https://www.cbsnews.com/news/trump-says-he-will-continue-outdoor-rallies-with-increased-secret-service-protection/
https://www.foxnews.com/us/trump-vows-more-outdoor-rallies-says-secret-service-substantially-step-up-after-admitting-failures
In addition, technically the Secret Service can’t really stop him. The relationship between ex-Presidents and candidates and their protection details and actual Presidents is much different.
The Secret Service can request no outdoor events (which they’ve done) but they can’t make the decision.