More than one-quarter of the USA's voters identify themselves as evangelical, a voter bloc that has long been courted by Republicans.
In addition, a similar political operative has successfully aided Democratic candidates in several states in the midterm elections.
Clinton's new hire is Burns Strider, an evangelical Christian who directs religious outreach for House Democrats and is the lead staffer for the Democrats' Faith Working Group, headed by incoming Majority Whip James Clyburn of South Carolina.
Incoming Speaker Nancy Pelosi created the group last year when Democratic strategists observed that the party lost ground in the previous election in part because candidates failed to reach centrist and conservative voters in rural areas, who tend to be churchgoers concerned with moral issues, according to the Washington, D.C.-based publication The Hill.
Strider was an aide to Pelosi when the group was formed and joined Clyburn's staff as policy director of the Democratic Caucus earlier this year, the paper reported.
"Observers of Clinton's expressions of faith say religion has always been important to her, that she attended prayer group meetings while first lady, and that she joined a Senate prayer group shortly after winning election in 2000," The Hill reports.
"Reporters anticipating Clinton's '08 presidential run wrongly discount her expressions of faith as cynical political maneuvering," the observers add.
Clinton is not the only potential Democratic candidate for the White House to launch efforts to appeal to religious voters.