Bengaluru: Buoyed by the emphatic victory of the Congress candidates in the by-polls held to three Assembly Constituencies of the State (Channapatna, Shiggaon and Sandur), followers of Chief Minister Siddaramaiah have planned to hold ‘Swabhimana Samavesha,’  a massive rally at Hassan, a JD(S) stronghold for decades,  on Dec. 5 as a show of strength of…