Where is the logical fallacy in this statement?

The question appears to conflate racist and non-racist attitudes with the popularity of immigration destinations, which is a bit of a non-sequitur.

The history of America reveals it to be both highly racist towards Native Americans, Africans, Asians, Jews, Italians, Irish, Mexicans, etc., and yet still remains a popular destination point for immigration in spite of it. 

The fact that it is a popular destination for immigrants does not mitigate its systemic and prolific history and expression of racist attitudes towards a wide variety of races, religions, genders, and ethnicities.  

The question implies an either/or premise when both possibilities are true. America is inherently racist and yet remains popular to immigrants seeking better lives and futures for themselves.

This seeming dichotomy can be further broken down by weighing the degree of racism prevalent in American attitudes versus other possible immigration destinations. Yes, America is racist but far less so than other immigration destinations.

For instance, Chris Mathews the former MSNBC anchor often pointed out that an Anglo foreigner might migrate to Japan but would never be accepted as native Japanese. Likewise, were they to move to Germany, France, Spain, China, Russia, or other countries they would not be considered natives of that country for generations to come. If ever.

However, in America, despite its deplorable history, national assimilation is much more possible than in these other countries. So now we're talking about racism relative to other destinations. This proves the point that America is decidedly racist but arguably less so than other alternatives and therefore understandably more popular.

The question conflates governmental racism (laws) with prejudices individuals may harbor. While it is a common argument, it is too “loose” to be the basis a meaningful discussion. 

There is a element of truth to the point of the question... the level of racism that exists in America is clearly not a significant deterrent for immigrants. But this doesn't mean there is no racism or racism isn't a serious problem—that wouldn't follow.

Overall, I wouldn't call fallacy because it is a question and not an argument. The wording is ambiguous so there could be many arguments derived from it. Rather than answer the question, the response could be "what's your point?" which would likely result in an argument being made:

This could be reasonably put in argument form as follows:

1. Immigrating to racist countries is not popular.
2. Immigrating to America is the most popular country to which to immigrate.
C. Therefore, America is not a racist country.

I would say thus is a valid argument. To see if sound, let's look at the premises.

Premise #2 is either true or not, a quick Google search leads me to believe it is true based on "popular" being the number of immigrants.

Premise #1 is where I can see much debate. If all countries are racist to some degree, then it follows that immigrating to racist countries IS popular. Of course, what is the threshold for a "racist country"? Immigrants might be fine with a few "microagressions" here in there if it means they aren't in fear for their lives.

Without setting objective metrics for "racist country," I think this wouldn't be an argument with supporting for defending.