The most recent Automatic Update for the WordPress Core made the 15px left edge padding disappear from my Static Front Page. It seems to be a Core issue, and not a theme problem. It worked fine until 3-4 days ago. Here's a link to my front page which jams the left column to screen edge. Doesn't happen anywhere else throughout the site: http://toolbox-4-websites.com/ .
Here's a link to WordPress forums asking for help: http://wordpress.org/support/topic/static-front-page-vs-bootstrap-3 .
Here's a link to another blogger's article on how the Bootstrap 3 grid works its magic: http://www.helloerik.com/the-subtle-magic-behind-why-the-bootstrap-3-grid-works .
Hope this helps out anyone else that runs into this problem.
(I prefer Bootstrap 3 to Bootstrap 2)