Why did the alliance between the Nationalists and Communists fail?

The "nationalists" and fascists battled against the "republicans" and communists in a civil war in the 1930s in

President nixon resigned from office in 1974 after he was informed that the senate would impeach him, as allowed in the constitution, for his actions in the watergate scandal. one of the key reasons that nixon’s actions became public was a) the freedom of press guaranteed by the first amendment. b) the right to confront witnesses as guaranteed by the sixth amendment. c) the limitation of judicial powers as defined in article 3 of the constitution. d) the prohibition against illegal search and seizure as guaranteed by the fourth amendment.

Approximately how many americans, from both the north and the south, were killed in battle during the civil war?