Tony Campolo: An evangelical is someone who believes the doctrines of the Apostle's Creed. That outlines exactly what we believe in detail. Secondly, an evangelical has a very high view of scripture though not necessarily inerrancy. And the third thing—we believe that salvation comes by being personally involved with a living resurrected Jesus. So I've defined evangelical in those three terms. There is a doctrinal statement, so that there is some content to what we believe. There is a source of truth, Scripture. And there is a personal relationship with Jesus.
What about salvation by grace through faith, based on the completed work of Christ, His righteousness imputed to us? Is this not central to our faith?
Invoking the Nicene Creed is how the Roman Catholic and Eastern Orthodox organizations are brought in and considered true churches. In light of the Galatian problem, what would Paul think? Would Tony think Paul too harsh? Maybe the anathema in Galatians was one of those parts that isn't necessarily inerrant.