I've seen a few of his speeches; very much social-justice Christianity, but Talarico bundles it up in a megachurch-friendly package. You never truly know someone's heart, but if all overtly Christian politicians espoused his version of the faith, I'd be a lot less terrified of them. Very possibly the most electable Dem candidate for Texas statewide office in a while.
Here's a more up to date article on the Senate possibilities.