KATY PERRY'S PRISMATIC tour is making it's way across America, and the pop-princess has spent some time in DC making a few social calls... 

 

 

The POP PRINCESS who said she'd write a campaign theme song for HILLARY CLINTON's possible presidential run, also hit up the JOE BIDEN at the WHITE HOUSE. He's the VP now, but no doubt wants to be the next POTUS... 

 

 

Perry - a big political supporter of President Obama - also took in some touristy-type things while in DC, and managed to skirt the local paparazzi in the process, too! 

 

Her second night in DC is tonight at the Verizon Center, and it's said that the guest list for this show is quite monumental, indeed...