Appearing on network morning news shows to preview Obama's address, Gibbs said the president will talk about some of the factors that led to Republican Scott Brown's upset victory over a Democrat in the special Senate election in Massachusetts.
"The president is going to explain why he thinks the American people are angry and frustrated," his spokesman said.
A member of the House Republican leadership, Rep. Eric Cantor of Virginia, said in a separate interview: "The American people want to hear that the president has listened and that the president has learned about what has gone on here."
Gibbs said "every president makes mistakes, including Barack Obama" and said Obama has "not been shy" about admitting that. At the same time, his spokesman said that Obama will "outline the fact that we've lived through one of the most challenging years in our country's history" and that Obama is "more hopeful about our future than ever."
He confirmed that Obama will embrace new cuts and other breaks for small businesses, to spur hiring and ease the country's double-digit unemployment rate. "Small businesses run our economy," Gibbs said. "Let's help them hire more workers."
"We need to stop pretending every day in Washington is election day," he added.
Said Cantor: "What I think we all want to hear is a real commitment ot putting this economy back on track, and it starts right here in Washington."
Gibbs appeared on ABC's "Good Morning America," CBS's "The Early Show" and NBC's "Today" show. Cantor also appeared on NBC.