Democratic Rep. John Larson lost Tuesday to former Hartford Mayor Luke Bronin in Connecticut's primary on Tuesday. 

Larson has represented central Connecticut since the late 1990s, and debates in the campaign focused heavily on generational change, CBS News reported. 

Bronin led Larson by just under 20 percentage points, or nearly 7,000 votes, late Tuesday. 

In the deep blue Hartford-area district, Larson, 78, and Bronin, 31, agreed on most key policy issues. The primary instead focused on whether Democrats should reelect a longtime lawmaker or back a younger candidate. 

Bronin raised just over $3 million during hte primary, while Larson pulled in $2.7 million.