A qualified no - Trumps relatability may not matter in this context. There are two parts to this: the message and the messenger.
Speaking in broad strokes here...
I believe more people are relating to (i.e. are inclined to agree with) Trumps [closed border] message and therefore do not need to relate to Trump the messenger.
Fewer people are relating to the open border message and thus, to help guide their analysis, people are looking to the messenger and finding them less relatable.
So there isn't an equal burden of proof / relatability and that's part of the problem. The left is already perceived as being out of touch and their loudest / most visible voices may not be helping that.
Speaking in broad strokes here...
I believe more people are relating to (i.e. are inclined to agree with) Trumps [closed border] message and therefore do not need to relate to Trump the messenger.
Fewer people are relating to the open border message and thus, to help guide their analysis, people are looking to the messenger and finding them less relatable.
So there isn't an equal burden of proof / relatability and that's part of the problem. The left is already perceived as being out of touch and their loudest / most visible voices may not be helping that.