Last week, Sen. John McCain (R-Ariz.) was forced to spend a couple of days offering tortured and nonsensical explanations for his once-strident opposition to holidays honoring Dr. Martin Luther King.

Ironically, Senate Republicans were, at the same time, blocking a resolution honoring another pioneering hero, civil rights leader César Chávez.

In fact, the Senate effort was the second consecutive year in which Republicans had blocked unanimous consent on a resolution that inoffensively “recognizes the accomplishments and example of a great American hero, César Estrada Chávez; pledges to promote the legacy of César Estrada Chávez; and encourages the people of the United States to commemorate the legacy of César Estrada Chávez, and to always remember his great rallying cry, ‘Sí, se puede!’ ”

Of course, like Martin Luther King before him, Chávez stood for principles vigorously opposed by the Republican Party. It’s no surprise that the GOP would stand in the way of honoring a man who demanded immigrants be treated fairly and with dignity, fought for worker rights and co-founded the United Farm Workers labor union, and who stood for better healthcare, education, and livable housing for all Americans.

In a climate in which Republicans have been trying to one-up themselves in scapegoating immigrants, none seem to have any appetite for honoring our nation’s most respected brown person.

Just look who is demanding Chávez be given his due respect — groups like the Congressional Hispanic Caucus, the Congressional Black Caucus and the AFL-CIO. For a party that now counts only four Latinos in Congress and no African-Americans, there is little impetus to be responsive to communities of color.

But just as McCain looks ridiculous in hindsight for so forcefully opposing the MLK holiday — and as politically damaging as that early recalcitrance appears today — failure to honor the greatest Latino hero in American history undoubtedly will appear similarly misguided and anachronistic in a generation.

The Pew Hispanic Center estimates that between 2005 and 2050, the Latino population will triple in size to 29 percent of the nation’s population. As I’ve discussed in previous weeks, what had been a traditionally swing demographic is now being driven solidly into the Democratic Party. While the main impetus for that shift is the GOP’s hateful stance on immigration, the disrespect shown Chávez on the Senate floor this week is emblematic of that party’s broader disdain for Latinos and their culture.

Neither have Republican efforts to block the creation of a National Museum of the American Latino in Washington, D.C.; nor the GOP filibuster of the DREAM Act, which would grant exceptional students who are undocumented a chance to legalize their status if they joined the military or went to college; nor their efforts to punish innocent children of undocumented immigrants by denying them access to SCHIP or Medicaid.

California Rep. Joe Baca (D) has introduced a bill in the U.S. House establishing a national holiday honoring Chávez. In an April 5 blog post on The Hill’s website, he wrote, “The creation of a national holiday will not only honor a great man but also educate Americans about César Chávez, helping ensure that his legacy continues to inspire others to work for the fair and just treatment of all people. César Chávez’s struggles for civil rights, labor rights and the environment led to victories that continue to impact people throughout our nation.”

It is precisely that impact that motivates Republicans to oppose such a holiday. To date, despite having 62 co-sponsors, not a single Republican has signed on.

That silence speaks volumes.

Moulitsas is founder and publisher of Daily Kos .