PHOENIX — His rallying cry echoes the late Cesar Chavez, the Latino activist who inspired legions with three simple words, “Si, se puede!”

The loose translation — “Yes, we can!” — has become Senator Obama’s call to arms.

But now, some are asking: Can he?

After a dismal showing among Hispanics in his Super Tuesday showdown with Senator Clinton, can Mr. Obama entice this key voting bloc? And, if not, what might that say about a color divide that extends beyond black-white in an ever-expanding brown America?

Going forward in a neck-and-neck race, the ability to win Hispanic voters will prove vital in the March 4 primary in Texas, where nearly 25% of eligible voters are Hispanic. It could even push a tight race into one camp or the other in places like Maryland and Washington, D.C., where the Latino share of eligible voters in this Tuesday’s primary hovers at just 3 and 4%, respectively.

“Let’s face it,” a popular Spanish-language radio host, Luis Jimenez, said, “Hispanics will vote for a woman president before voting for someone who is African-American.”

While the overall tally of Super Tuesday’s string of contests was hardly conclusive in determining the ultimate Democratic presidential nominee, the results among Hispanics spoke volumes: Mrs. Clinton, exit polls showed, won 63% of Hispanic voters, helping propel her to victory in places like Arizona and California, where a whopping 67% of Hispanics backed her.

Even in Mr. Obama’s home state of Illinois, where he soundly beat Clinton, polls showed he merely split the Latino vote.

Is this about familiarity, a Johnny-come-lately strategy and a shortage of big-name Latino endorsements, or something less tangible and more provocative — a reluctance among Latinos to support a black candidate?

The suggestion inflames Federico Pena, who served in President Clinton’s Cabinet and now sits as a national co-chair for the Obama campaign.

“That would say that Hispanics are racist. We are not,” he said. “What is really going on here is that Hispanics simply don’t know this candidate, and he happens to be African-American and he happens to be named Barack Obama.” Louis DeSipio, a political scientist who chairs the Chicano studies program at the University of California, Irvine, agreed: “It’s not a rejection of Senator Obama. It’s an affirmation of their support for Senator Clinton.”

Clearly, Mrs. Clinton had advantages over Mr. Obama that had nothing to do with color.

She is well-known and well-liked among Hispanic voters who remember fondly her husband’s presidency and the inclusion of Latinos such as Mr. Pena. She won coveted — and early — endorsements of prominent Hispanics, including Mayor Antonio Villaraigosa of Los Angeles, who traveled to Iowa and Nevada to campaign for Mrs. Clinton, and Dolores Huerta, who co-founded the United Farm Workers with Chavez.

She also got a jump-start wooing Hispanic voters on the ground and on the airwaves, while Mr. Obama’s initial underdog status had him focused on early contests in Iowa, New Hampshire, and South Carolina. In January, Mrs. Clinton went door-to-door in a largely Hispanic neighborhood in Las Vegas, and turned up a day later at King Taco on Los Angeles’s Cesar Chavez Boulevard with Mr. Villaraigosa.

“Hillary Clinton has a long relationship with the Hispanic community … based on her work but also her husband’s presidency, so it’s not surprising that Hispanics went for her more than Obama,” said Susan Minushkin, deputy director of the nonpartisan Pew Hispanic Center. Ms. Minushkin was surprised that Mrs. Clinton’s numbers among Hispanics weren’t even higher.

A December survey by the center found Democratic-leaning Latinos who were registered voters overwhelmingly supported Clinton. Still, that same survey found that Mr. Obama drew more support among those voters than Governor Richardson of New Mexico — himself a Hispanic who speaks Spanish fluently and who lived more than a decade in Mexico City.

A November Pew study found that 74% of Hispanics who were familiar with Mr. Obama regarded him favorably. However, the percentage of those polled saying they had never heard of Obama, or were unable to rate him, was higher among Hispanics than blacks or whites.

Still, others wonder whether such surveys accurately reflect the reality on American streets, where tensions among blacks and Hispanics have increased in past years as Hispanic immigrants pour into inner-city neighborhoods, competing with their black neighbors for jobs, housing, services — and a seat at the table on local school boards and town councils. Hispanics have surpassed blacks as the nation’s largest minority, comprising about 15% of the American population today.

“We’ve been fighting in this country for our place — and so is every minority,” Mr. Jimenez said, surmising that Hispanics’ Super Tuesday snubbing of Mr. Obama stems from viewing him as “a competing minority rather than a serious candidate for president.”

Mistrust fueled by racial stereotypes that play out in Hollywood and the press may also contribute, along with prejudices that may have first formed in the class-driven societies of some Hispanics’ native lands, where darker-skinned indigenous citizens are sometimes looked down upon by those with lighter skin and a Spanish heritage.

Armando Navarro heard mentions of race when trying to convince friends to vote for Mr. Obama. Mr. Navarro teaches ethnic studies at the University of California, Riverside, and is coordinator of the National Alliance for Human Rights, a Hispanic activist organization.

Color, he said, while not THE factor in the Super Tuesday results was A factor.

“It stems from our own experience as a people,” he said, but also that competitiveness that Mr. Jimenez cites — “the fear that with a black president, ‘they’re’ really going to be in and ‘we’re’ going to be out.”

Consider the view of another voter, Gustavo Sanchez, a Los Angeles painter originally from Mexico.

“Obama is African-American so his support would naturally come more from blacks. And I think he would support blacks more,” said Mr. Sanchez, who voted for Clinton in the California primary.