He shouted slogans, why put quotation marks?

In order to highlight the importance of slogans and attract attention.

Quotes can distinguish slogans from other words and make them more eye-catching and prominent. Slogan is usually a concise and powerful declaration or slogan, which is used to express a specific point of view or call for action. By adding quotation marks, we can emphasize the independence and importance of slogans and make them more conspicuous in the text. Doing so will help attract readers' or listeners' attention and make it easier for them to understand and remember the content of the slogan.