She was born to Irish immigrants Joseph P. and Mary Elizabeth Murray Clyens (an anglicization of the Gaelic name Mac Giolla Chaillín), in Ridgway, Pennsylvania.

In that party's 1890 campaign she made more than 160 speeches and claimed credit for the defeat of Kansas senator John Ingalls.

She believed that big business had made the people of America into "wage slaves", declaring, "Wall Street owns the country.

Emporia Gazette editor William Allen White, who did not share her political views, wrote on one occasion that "she could recite the multiplication table and set a crowd hooting and hurrahing at her will".

One reporter described her as "untrained, and while displaying plenty of a certain sort of power, is illogical, lacks sequence and scatters like a 10-gauge gun.

"[10] The Wellington Monitor called her “a miserable character of womanhood and hideously ugly of features and foul of tongue”.

Her venomous tongue is the only thing marketable about the old harpy, and we suppose she is justified in selling it where it commends the highest price.

Lease felt the attempt to have her removed stemmed from her determination to have women's suffrage and temperance as her main focus at the Populist Party's next state convention.

[14] Despite her fallout with—and the eventual destruction of—the Populist Party, Lease felt that their work and efforts were ultimately rewarded with the election of Theodore Roosevelt and the national push for reforms that she had championed years earlier: "In these later years I have seen, with gratification, that my work in the good old Populist days was not in vain.

Literary scholar Brian Attebery claimed Mary Elizabeth Lease to have been the model for Dorothy in L. Frank Baum's The Wonderful Wizard of Oz.

Science will take, in condensed form from the rich loam of earth, the life force or germs now found in the heart of the corn, in the kernel of the wheat, and in the luscious juices of the fruit.

A small phial of this life from the fertile bosom of Mother Earth will furnish man with subsistence for days.