Many politicians, especially today, like to claim "outsider status"--in that they aren't burdened by a history in Washington. The down side to this is that they also don't have many political alliances.
Answer:
Legislative: makes all laws, declares war, regulates interstate and foreign commerce and controls taxing and spending policies.
Executive: responsible for enforcing the laws of the land
Judicial: According to the Constitution, "[t]he judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish." The Federal Judicial Center is the education and research agency for the federal courts. They also interprets the laws. The state judges are elected by the citizens rather than being appointed.
(sorry about only 1 job for the Executive branch)
Some reasons were that Native Hawaiians were against U.S. annexation, and the controversy of how US marines used force against the Queen Liliuokalani of Hawaii (held her at gunpoint) and also the fact that President Grover Cleveland himself was against annexation.