In September, President Trump visited Houston for a massive rally with Indian Prime Minister Narendra Modi. With his signature directness, Trump made an appeal to Indian American voters broadly.

He had come, he told the audience, to “express my profound gratitude to the nearly 4 million amazing Indian Americans all across our country.”

“You enrich our culture, you uphold our values, you uplift our communities, and you are truly proud to be American,” he continued. “And we are proud to have you as Americans. We thank you. We love you. And I want you to know my administration is fighting for you each and every day.”

Trump does this sort of thing, making sweeping claims about groups and describing in vague terms how he’s helped them, such as when he points to drops in unemployment (as he did in Houston). It’s a new style of a standard tactic, reaching out to specific demographic communities with direct appeals.

In February, Trump’s reelection campaign followed the event with a small advertising buy targeting Indian Americans. But even then, change was in the air. Sen. Kamala D. Harris (D-Calif.), once a candidate for the Democratic presidential nomination, would soon endorse former vice president Joe Biden, who went on to win the party’s primaries in commanding fashion. On Tuesday, Biden named Harris as his running mate. With that, Trump’s efforts to convince Indian American voters probably hit a significant roadblock.

While Harris is primarily identified as one of the country’s leading Black politicians, given her father’s background, she’s also the daughter of Shyamala Gopalan, who immigrated to the United States from India as a young woman.

It’s simplistic to assume voters will necessarily support candidates who share their demographics, but there’s certainly ample evidence that such similarity can play a role. In this case, there’s an added reason to think Indian Americans would probably support Harris: The population is heavily Democratic.

Data from L2, a political data firm, indicates there are about 1.6 million voters in the United States who are probably Indian immigrants, or of Indian descent. (In most states, it’s difficult to be precise. L2 uses state data where it’s available and name-matching where it isn’t.) Of that population, a plurality are Democrats. For every Republican L2 identifies as probably Indian American, there are three Democrats.

Many of those voters live in areas where the results of the November election aren’t really in doubt: California, the Boston-to-D.C. corridor and other large cities, for example.

As a percentage of the population in various designated market areas (which generally overlap with broad metropolitan areas), the distribution is more interesting, including disproportionately heavy representation in Texas and in California’s Central Valley, both more conservative areas of the country.

This, of course, raises the question of how Harris’s addition to the ticket might influence the election results in close states.

Again, it is hard to determine the extent to which voters will be influenced by shared demography. But there are some tantalizing hints in the L2 data. In addition to populations in Texas cities, there are larger Indian American voter populations in states that are expected to be close in 2020, including Minnesota, Georgia and Michigan.

As the map above shows, likely Indian American voters in Texas and Minnesota tend to skew more Republican than Democratic, though many are independent or third-party. But that’s the point: If Harris can help bring over more moderate or even Republican votes, that helps the ticket significantly.

For the most part, the number of likely Indian American voters in states is fairly modest. But in a number of potential swing states, the population makes up a significant chunk of the 2016 margin between Trump and Hillary Clinton in the state.

Those numbers for Michigan and Pennsylvania are interesting, where the number of likely Indian American voters is larger than the 2016 margin. More interesting, though, are the ones for Florida, where the number of likely Indian American voters is two-thirds the 2016 margin. There are twice as many Democrats as Republicans, but persuading independent voters to vote Democratic instead of Republican could be significant.

As could increasing turnout. In 2016, more than 4 million people who’d voted for Barack Obama in 2012 did not vote. Most were non-White. If Harris spurs infrequent Indian American voters to the polls, that benefits her ticket, too.

Of course, Democrats also clearly hope she will have a similar effect on Black voters, which could itself make a difference in close races in Michigan or Pennsylvania. Or Florida, or Georgia, or Texas. There is little indication that Trump’s repeated citation of the once-historically low unemployment rates for Black Americans is winning him many votes.