Why does it say "Ra'isi Rasha Aritz"?
Radak: [I saw an evil tyrant]; he is strong and succeeds.
Malbim: Even though sometimes I see an evil tyrant, and he is rooted in this world with children and wealth like a fresh tree full of roots and branches
What is the meaning of "u'Mis'areh"?
Rashi: It is rooted. This is like "Aros Al Ye'or" (Yeshayah 19:7), or 'Ilan she'Nifsach u'Me'orah b'Kelipah' (Uktzin 3:8).
Why does it say "k'Ezrach Ra'anan"?
Rashi: Like one of the natives of the land, who are rooted and full of property.
Rashi citing Menachem: He gets moist and sprouts like a rooted tamarisk. Ezrach is one of the natives, a person of roots.
Radak: Ezrach is a moist tree, for its beauty and moistness are revealed to all, just like an Ezrach person, all know him and his family - the opposite of a Ger.