Help with U.S history?

I'm working on an essay; I have one half of it, but I'm struggling to find the other.

The essay question basically goes as follows:

What were the main motivations (at least three) that finally caused the U.S. to intervene in World War I?

We're supposed to detail the reasons for U.S. involvement, and then provide arguments against why someone would not consider these factors that motivated the U.S. to become part of WWI. I'm able to detail the reasons as to why the U.S. involved itself, but I can't find arguments against them?

My reasons for U.S. involvement are:

Americans carry a cultural ties to the British due to common ancestry

Americans traded with the Allies far more often than they did with the Central Powers

German submarine warfare

The Zimmerman note

Russia switching to a more representative form of government, allowing the U.S. to claim that the conflict against the Central Powers was one of fair representation.

Any help is appreciated!