Not really Krishna the superstar and father of Mahesh Babu is not with the Congress. His brother Adiseshagiri Rao is with YSRC and he was close to YSR the then CM of AP. But Mahesh babus brother inlaw Galla Jay Dev is an MP from TDP. Once or twice Mahesh campaigned for Jay Dev, but that does not mean he is with the TDP.
That is for individual interest and relation that Mahesh travels with Jayadev. In the same fashion Krishna, the superstar obliged to have the kanduva of Congress around his neck. The Congress candidate is seen here greeting Krishna. Krishna neither can say yes or no to the Kanduva.
But as of now, Mahesh is chummy with KTR the Minister for IT. The Minister also did some promotion fro Mahesh movie earlier. Bharat ane Nenu was endorsed by KTR earlier. So if some other party candidates greet Krishna he cannot say no to them.
But generally, people say Krishna is a sympathiser for the Congress during Indira Gandhi days.