The United States Constitution grants the POTUS the pardon power for federal crimes and state offences recognizable under state criminal law.
“But issuing pardons to his own friends, associates and relatives could be a perilous path for Trump, creating additional exposure on two levels, criminal and political — both flowing from an important proposition that is often overlooked in the debate over presidential power. ”
It is up to both Congress and the federal prosecutor to determine whether Trump’s pardons violates norms constitutionally and statutorily.
Political critics are treating this incident as severe as the Watergate scandal, which some argue that it can also lead to the same consequence: impeachment.
Therefore, while Trump is trying to defend his first year as POTUS using his pardon power, it can nonetheless be the last nail in the coffin.
Source: How the pardon power could end Trump’s presidency – The Washington Post