From the piece:
Sen. Mike Lee: "People need to understand that the reason we worry about raising taxes on anyone – even raising taxes on the rich – it’s not that we’re looking out for the rich, it’s not that we’re concerned that the rich won’t be able to fend for themselves, because they will. It’s because we worry about the consequences that will inevitably result from that action and that will hit the poorest among us the hardest."
If you are convinced that raising taxes on the rich by a modest amount would tank the economy, then his reasoning makes more sense. But there is not a ton of evidence for that claim.