Because that could mean he could lift term limits and he could be the president until the day he dies.
That has been one of
thishis dreams ever since he was installed in Oval Office the first time. He has been trying to become the "emperor" just as long. For example the chairman of the Joint Chiefs of Staff general Mark Milley described the last months of his first term by comparing it with the Nazis and the Reichstag Moment they pulled off, specially after Trump's goons attacked government buildings after the election and all the mess he caused back then...
Even recently a clip came out of him talking to the Zionist Zelensky and was fascinated about the idea of being able to remain in office even after the term ends, in case the country was at war!