On Monday, Narendra Modi's BJP achieved a landmark victory in West Bengal, defeating Mamata Banerjee's Trinamool Congress (TMC) after 15 years and conquering a state with an electorate exceeding 100 million, larger than Germany's. This breakthrough completes the BJP's expansion into eastern India, rooted in a decade-long project where the party consistently polled around 39% and surged to over 44% by merging welfare promises with Hindu consolidation, while TMC's welfare politics and organizational strength waned. Despite the BJP's thin grassroots machinery, it offset TMC's strong support among women and Muslim voters (27% of population) through targeted campaigns and controversies over electoral roll revisions affecting minorities. The win strengthens Modi and Home Minister Amit Shah, who led the campaign, and may reshape BJP's succession politics.