Bryant will replace Gov. Haley Barbour (R), who is stepping down after two terms.
Bryant dramatically outraised DuPree, $4.3 million to $1.2 million.
DuPree made history as the first black major party candidate for governor since Reconstruction. But he could not overcome the sharp Republican shift in the South over the past decade, along with dissatisfaction with President Obama.
Republicans also took over state House for the first time since Reconstruction. Democrats previously held a 68 to 54 majority in the lower chamber. That victory means Republicans will completely control the redistricting process in the state.