The last time a U.S. president faced a strong movement for impeachment for actual impeachable offenses, one of the major road blocks was fear that an unpopular vice president would take his place, and this road block was removed when Spiro Agnew resigned in the face of criminal charges of cheating on his taxes.
As every American is aware, including even those who have never heard of impeachment, the primary problem with impeaching Trump is the horror of a president Pence. For a long time I tried to explain to people that this was stupid. Pence is already running the show. Impeachment is about placing the executive branch under the rule of law, not about the trivial matter of what individual holds what office for a few years. A President Pence with a Congress that impeaches people would be better than King Donald with Congress acting as court jesters. Impeachment and removal from office are two different things. Et cetera. It doesn't matter how many reasons you provide, the U.S. public may never support impeachment of Trump as long as Pence is vice president.