The first noticeable similarity between the "Cross of Gold" speech from William Jennings Bryan and the "History is a Weapon" speech from Mary Elizabeth Lease is that both speakers aim to find a "common ground" between them and their attendance. They try to achieve this by constantly using "we" in their phrases. In other words, trying to show their audience that they are like them. They are one of them.
A second similarity is that they both try to personify a "common enemy". They emphasize on a particular name or names, but rather a more general entity which is trying to put obstacles to the hard-fought ideals and goals that the groups these both speakers represent. This is a very useful tool in trying to get the backing of the audience.