According to the us constitution, which branch of government has to declare war?

Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States

Explanation:

The president can declare war because he is the leader of the nation. He has full contact with any of the other nations leaders. If he feels like he needs war, then he needs war.

bias opinions and using a push pull

populist movement, in u.s. history, politically oriented coalition of agrarian reformers in the middle west and south that advocated a wide range of economic and political legislation in the late 19th century. thus in 1892 their leaders organized the populist, or people's, party, and the farmers' alliances melted away.