BENGALURU, April 6 -- The Congress is confronting an unusual test of its internal cohesion in the Davanagere South Assembly by-election, where discontent among Muslim leaders and a surge of rebel candidates have raised the prospect of vote-splitting in a constituency long shaped by the party's core support base.

The trigger for the unrest is the party's decision to field Samarth Mallikarjun, a family member of late MLA Shamanur Shivashankarappa, instead of a Muslim candidate. The choice has unsettled sections of the community, which has consistently sought representation since the constituency was carved out in 2008 and remains a significant electoral bloc, with roughly 80,000 voters in an electorate of 2.32 lakh.

With the April 9 poll ...