The BJP stared at a massive setback as votes were counted in crucial by-elections today, with the Samajwadi Party leading in both Gorakhpur and Phulpur, parliament seats vacated last year by Chief Minister Yogi Adityanath and his deputy Keshav Prasad Maurya as they joined the state government after the BJP's landslide win in the assembly elections. For arch rivals, Samajwadi Party and Mayawati's Bahujan Samaj Party, a tentative political experiment has brought big returns.