WASHINGTON — Monday’s inaugural may be President Barack Obama’s big day, but Martin Luther King Jr. will loom large over the festivities.

A quirk in the calendar pushed Obama’s public swearing-in onto the national holiday honoring the slain civil rights leader, and inaugural planners have taken pains to acknowledge that fact.

Going into his second term, Obama seems to have put King at the front of his mind, too.

The president has referenced King in speeches, and a weekend of inaugural festivities opened Saturday with a National Day of Service in King’s honor. Obama and his family helped spruce up an elementary school in southeast Washington.

The Obamas also have performed community service work on the King holiday in each of the past four years.

Obama spoke at the 2011 dedication of a memorial to King on the National Mall and is likely to include King in his inaugural address on Monday.

The president has said King is one of two people he admires “more than anybody in American history.” President Abraham Lincoln is the other.

In a nod to that admiration, Obama will take his ceremonial oath of office Monday using Bibles owned by both men. Lincoln’s Bible, which Obama also used in 2009, will rest on top of King’s, which is larger.

“The movements they represent are the only reason that it’s possible for me to be inaugurated,” Obama said in a video released by inaugural planners.

Obama is perhaps the most high-profile result of King’s quest for civil rights and racial equality in the U.S. He credits King for his own political victories, particularly the 2008 election win that lifted him over the highest hurdle for minorities in American politics.

Even with that, there are distinctions in their styles. While King was a staunch advocate for the poor and downtrodden, Obama has been faulted by critics who say he’s been reluctant to push issues of concern to black people and take steps to reduce high rates of black unemployment.

Where King opposed wars in general and was an unwavering advocate of nonviolence, Obama has shown himself to be willing to target and kill leaders of terrorist groups overseas.

Fredrick Harris, director of Columbia University’s Center on African-American Politics and Society, argues that Obama’s reluctance to bring black issues to the forefront undermines the work of King and other civil rights leaders whose efforts made his presidency possible.

“Dr. King died in 1968 fighting for low-wage garbage workers in Memphis, Tenn. He was starting a national poor people’s movement to address the issues of poverty,” Harris said.

“With the president, a Democratic president for that matter, who has spoken less on race or the poor or poverty than any Democratic president in a generation, it is problematic when we think of that aspect of King’s legacy.”

One of eight floats scheduled to participate in the parade down Pennsylvania Avenue between the Capitol and the White House on Monday will honor King, featuring his image and a representation of his quote “out of the mountain of despair a stone of hope.”