per the context given, how would illiterate politicians able to vote?

Context: A lettering guide template is a special type of template used to write uniform characters. It consists of a sheet of plastic or other material with cut-outs of letters, numbers, and other shapes used especially for creating technical drawings. For decades they have been essential for lettering a drawing nameplate so text and other designs could be made quickly and uniformly.

Although they have been superseded by the use of computers, during the greater part of the last century they were used to relatively ease the lettering process in the creation of technical drawings. They were an indispensable tool for architects and technical illustrators in general, for labeling their drawings and plans but also for the description of projects, in which it was good practice to use a lettering template to achieve uniform and well-written text.

A lettering template could also be used by people illiterate or semi-illiterate to learn to type, or improve their handwriting. In the course of political history some politicians, such as Bettino Craxi, have used them to help people with writing difficulties. They distributed cardboard templates with the sequence of characters of their last name, so they could be easily written during the voting process.

Answer: They used lettering guide templates made of cardboard with characters of their last name