Did the SDS attract primarily blue collar workers?

The acronym SDS, you will recall, stands for Students for a Democratic Society. The name of the organization tells you right away that it is made up of students, and they were generally college students (high school students are not as well prepared or motivated to engage in political activity, on the whole). So no, these were not blue collar workers. Blue collar workers did not join the SDS, they joined the AFL-CIO.