This is a tough question to answer. Although it is in the Senate's constitutional right to conduct an impeachment trial, the Constitution states an an impeachment is only for a sitting US president and does not have much guidance for a non-sitting US president. As of now, Donald Trump is a private citizen and therefore the impeachment may not directly effect him in the same way as a sitting US president. However, an impeachment where he is found guilty will disallow him from running for office again in the future.
Although there are many arguments and opinions to this particular subject, the current impeachment seems to be more politically motivated than actually needed.
