Ben Carson, the sole black candidate running for president in either major party, is aiming to double the GOP’s share of the black vote if he makes it to the general election. Marco Rubio is Latino, and his campaign has said he can substantially boost the party’s performance among Latino voters. And perhaps they can. But Louisiana Gov. Bobby Jindal’s exit from the presidential race should make the Republican Party think twice about the idea that putting a minority candidate on the ballot will be enough to make inroads with minority voters.

Jindal, who is Indian-American, ran as a Christian conservative. He earned high favorability ratings among the mostly white evangelical voters in Iowa but did little to appeal to minority voters, railing against the idea of “hyphenated Americans” and saying, even in his exit interview, that “immigration without assimilation is not immigration; it’s an invasion.” Some South Asian-Americans took to mocking Jindal on Twitter with satirical hashtags including #BobbyJindalIsSoWhite and #Jindian.

Research shows that minority candidates can be successful in drawing out co-ethnic minority voters. Professor Taeku Lee, managing director of the public-opinion research firm Asian American Decisions, said, “If you ask minority voters in an abstract way, ‘If two candidates were equally qualified and you had the chance to vote for a co-ethnic candidate, [would you?]’ then very large majorities of African-American, Latino and Asian-American voters will say ‘yes.’” These conclusions often hold true in the abstract, or in races for local office, which are often nonpartisan, Lee said, but it is difficult to draw any conclusions from the research about national elections, in which partisanship is a much stronger force. When Latino voters are asked whether they would vote for a co-ethnic candidate, Lee said, they may have in mind someone who matches their political ideology: “They are probably thinking of someone like Luis Gutierrez and not Ted Cruz, or an Asian-American is probably thinking of a Judy Chu and not a Nikki Haley.”

Jindal’s political career suggests as much. Jindal once embraced his Indian-American identity, speaking proudly about being Indian-American in interviews and, when he was a U.S. representative, co-sponsoring a bill to recognize the accomplishments of Indian-Americans. Even as a Republican, Jindal initially had some support among Indian-Americans, an otherwise strongly Democratic-leaning group. We were able to approximate the amount of money Jindal raised from South Asian-American donors by running an algorithm that uses the phonetics of donor names to estimate their ethnic identity. During Jindal’s first gubernatorial campaign, in 2003, South Asian-Americans donated an estimated $667,000, or 19 percent of the $3.5 million he raised from individual donations. During his much more expensive 2007 and 2011 campaigns, that figure dropped by about half and made up only about 4 percent of the approximately $8 million that he raked in from individual donors during both of those campaigns.

Because contributions of less than $200 are omitted in federal donor records, we used only Jindal’s gubernatorial campaigns in this chart. However, running the same algorithm on the itemized donations (over $200) for Jindal’s 2016 presidential campaign shows that he continued to receive less than an estimated 4 percent of his large donations from South Asian-American donors.

South Asian-Americans ended up treating Jindal like any other Republican. A survey before the 2014 midterms of more than 1,000 Asian-American likely voters found that only 14 percent had a favorable view of Jindal. Co-ethnicity didn’t outweigh policy differences between Jindal and Asian-American voters. In 2008, an exit poll by the Asian American Legal Defense and Education Fund found that 80 percent of Asian-American voters supported extending health insurance and medical coverage to all people regardless of immigration status. Asian-Americans also overwhelmingly support gun-control legislation and increasing the minimum wage. Jindal didn’t support any of that.

After Mitt Romney lost to President Obama in 2012, the Republican National Committee issued an “autopsy report” on what went wrong, highlighting the GOP’s failure to appeal to non-white voters. It concluded, in part, “If we want ethnic minority voters to support Republicans, we have to engage them and show our sincerity.” Republican candidates in 2016 would do well to heed this advice. A poll released just last month by Latino Decisions found that 45 percent of Latinos believe the Republican Party is sometimes hostile toward Hispanics/Latinos. That number has doubled since 2012. The lesson, Lee said, is that “unless candidates like Carson, Cruz and even Rubio begin to better connect their descriptive identity to policy proposals that speak to where black, Latino and Asian voters are on these issues, co-ethnic mobilization will only go so far.”

Asthaa Chaturvedi contributed research.