It is unlikely that a digital dollar would pose a threat to bitcoin. While a digital dollar may provide some competition for bitcoin, the two are fundamentally different and serve different purposes. Bitcoin is a decentralized digital currency that operates independently of any government or central authority. A digital dollar, on the other hand, would likely be issued and controlled by the government, similar to how physical dollars are currently issued and controlled. As such, a digital dollar would not be a direct threat to the existence of bitcoin, but it could potentially compete with it for adoption as a means of digital payment.