Indiana Mayor -- I'm Cool With 2 Chainz ... He Doesn't Attract Bad People Like Chief Keef

The Indiana mayor who shut down Chief Keef's concert over the weekend went and mugged for the camera with rapper 2 Chainz ... because he says Chainz is all about having a good time while Keef attracts a bad element.

Hammond Mayor Thomas McDermott tells us he pulled the plug on Keef's non-live, hologram performance Saturday night because of Keef's "anti-cop, pro-gang" lyrics.

As for why McDermott took a pic 2 days later with 2 Chainz ... he says the rapper's lyrics are innocuous and the crowds are more chill. Perhaps McDermott hasn't heard the song, "We Own It," in which 2C raps ...

We got big guns, been graduated from knives
It's the day in the life and I'm ready to ride