Modal window not displaying

I’m trying to determine why I can’t display a modal popup on my WordPress website. I’ve tried a few different plugin for an automatic modal window yet none of them seem to work. Here’s a link to my site:

http://www.tacticaldistributors.com/blog

If anyone can shed some light on troubleshooting this, I’d greatly appreciate it.