Does everyone who follows me on Twitter automatically follow me here?

Yes, once they have signed into We Vote.

When you sign in / login with your Twitter account, we search our database to see if any of the organizations or people you follow on Twitter have public endorsements stored in We Vote. If they have public endorsements stored in We Vote, your account automatically Follows their account so that you can see their opinions next to your ballot.

When someone following you on Twitter signs into We Vote, their account will automatically follow your public We Vote account, so that they are able to see any endorsements you make and mark as "Public". Someone following you on Twitter is not able to see your endorsements marked "Friends Only".