I do not know if it is still done by anal retentive Republican operatives but in the past they handed out litmus paper; a two-page loaded questionnaire to test the mettle of would be Republican office holders. It might have only been SD 35 doing so then, or Freedom Club, but somebody "winnowed" things with two pages of super narrow litmus paper implying precisely the answers wanted or in the alternative implicitly saying to go away. You could call it "little tent litmus paper."
From years back, person and year not mattering as much as generic impulse of the theme, the below question-and-answer loyalty oath monstrosity is presented as a true and accurate example of political imbecility:
Click each image to enlarge and read. '50's loyalty oaths were less onerous.
It is a bit dated in not asking which restroom a transexual individual should use.
Then the final step. Turn in your questionnaire in person humming "Yes, Jesus loves me" and wearing an expensive suit, Trump tie, and conspicuously sporting one of those made-for-the-GOP cloisonné flag lapel pins [made in China].