We have explained in our article Biblical Formatting located on the world wide web at http://www.Rashiyomi.com/biblicalformatting.pdf, that the Biblical Author indicated bullets by using repeating keywords.

That is, if a modern author wanted to get a point across using bullets - a list of similar but contrastive items - then the Biblical Author would use repeating keywords. Today's verse illustrates this principle.

Verse Gn49-03d discussing the greatness that Reuven should have had states Reuben, thou art my first-born, my might, and the beginning of virility; [you have]
• additional stature, and
• additional might.

The bulleted structure indicated by the repeating underlined keyword additional creates a bulleted atmosphere. Rashi explains:
• You should have had additonal stature, the priesthood
• you should have had additional might, monarchy.

Advanced Rashi: Why did Rashi equate stature = priesthood and might = monarchy. A review of the logic involved would be illuminating. First the bulleted structure indicated by repeating keywords requires us to see an unspecified emphasis of distinctness in the bulleted items. Next it seems reasonable to associate might = monarchy. There is no obvious association with stature. But it is reasonable if we have already used up monarchy to associate stature with some other Jewish hierarchical social structure. Two obvious candidates are prophecy and the priesthood. Prophecy does not belong to any tribe but rather to any person who aspires to it. So Rashi associates stature=Priesthood.