County attorney (with the gallantry of a young politician). and yet, for all their worries, what would we do without the ladies?

what is the primary purpose of these stage directions?
to further establish the time period

to indicate a character’s tone of voice

to direct actions that take place onstage

to describe a character’s thoughts

The primary purpose of these stage directions (with the gallantry of a young politician) is to indicate a character's tone of voice.
Given that he is referring to the ladies, he has to change the tone of his voice a bit to appeal to them more. He cannot speak in a manly voice which he would normally use while speaking to other men, but rather appear more suave and gentleman-like.