Tennessee Democrats are looking at Thursday's primary as a critical step in the rebuilding urged by internal analysis. Since 2006, Democrats have lost 19 House seats and three seats in the Senate, placing them firmly in the minority of the two chambers. Another nine Democratic incumbents announced earlier this year they would not run again. Meanwhile, districts newly redrawn by Republicans are pitting several incumbent Democrats against each other. Nevertheless, Democratic leaders said they're optimistic about their 47 candidates. House Democratic Caucus Chairman Mike Turner said he believes his party can win at least six races.