No, but it's closely upstream of certain political beliefs and the Left has attacked our ability to talk sensibly about these issues by conflating the two.
I assume that you will agree that racism has two common definitions[1]:
1. a belief about facts: that there are distinct human subspecies that differ biologically from each other in various ways
2. a description of behaviour: favouring one human subspecies over another in certain matters
An example of the first kind would be the observation that Kenyans, particularly from the Nandi subtribe of the Kalenjin tribe seem to outperform every other ethnic group on distance-running, and the hypothesis that "favorable somatotype" (i.e. an innate biological characteristic of this group) may be contributing to this.
An example of the second kind would be the factual observation that (at least in the US), increased ethnic neighbourhood diversity is correlated with decreased with lower trust in others and lower neighbourhood social cohesion[4]. Another example would be the theoretical observation (based on agent-based modeling) that diversity and a sense of community are incompatible community properties[5].
Now the point I want to make is that while racism as defined above (either a statement of fact, or a description of human racial preferences) is not in itself a political belief, it can very certainly form, contribute to, or be the basis of certain political beliefs.
As I hinted at with the start of this comment, I think your statement is a symptom of broader confusion on the Left about racism caused by lack of clear definitions and eagerness to overuse "racist" as a slur and as a catch-all for people or ideas they don't agree with[9]. Here's a list of mistakes that many on the Left make and that combine to make it really hard to address these issues clearly and without hysteria. Hopefully it will help clear up some confusion and provide opportunity for some exchange of thoughts:
1. Conflating the two definitions given here. For example, by assuming that those who think there are biological differences between certain human subspecies (first definition) also think discrimination based on these group characteristics (second definition) is okay.
2. Conflating beliefs about biological differences (first definition) between human subspecies with beliefs about the supremacy or inferiority of certain human subspecies. That's why the terms "racism" and "white supremacy" are often seen to be used almost interchangeably.
3. Conflating favouring one human subspecies over another (second defition) with the supremacy of one's own subspecies. For example, Enoch Powell opposed mass immigration to Britain, but also regarded "many of the peoples of India as being superior in many respects [...] to Europeans."[6]
4. Believing that whoever opposes or is skeptical about multiracial/multiethnic societies is doing so on racist grounds (as defined above, so either because he believes certain human subspecies are less well adapted to life in some society, or because he believes people have a natural preference for more or less monoethnic societies and that it therefore makes pragmatic political sense to favour monoethic societies). For example, someone may oppose it because he values and wishes to maintain human racial diversity and believes (not unreasonably so[8]) that multiethnic societies are eroding racial diversity.
5. Believing that opposition to multiculturalism is racist. This is self-explanatory and should be obvious regardless of whether you oppose or support multicultural or multiethnic societies.
[1] https://en.wiktionary.org/wiki/racism
[2] Tucker, Ross, Vincent O. Onywera, and Jordan Santos-Concejero. “Analysis of the Kenyan Distance-Running Phenomenon.” International Journal of Sports Physiology and Performance 10, no. 3 (April 1, 2015): 285–91. doi:10.1123/ijspp.2014-0247.
[3] Larsen, Henrik B. “Kenyan Dominance in Distance Running.” Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 136, no. 1 (September 2003): 161–70. doi:10.1016/S1095-6433(03)00227-7.
[4] Putnam, Robert D. “E Pluribus Unum: Diversity and Community in the Twenty-First Century the 2006 Johan Skytte Prize Lecture.” Scandinavian Political Studies 30, no. 2 (2007): 137–174.
[5] Neal, Zachary P., and Jennifer Watling Neal. “The (In)Compatibility of Diversity and Sense of Community.” American Journal of Community Psychology 53, no. 1–2 (November 6, 2013): 1–12. doi:10.1007/s10464-013-9608-0.
[6] "What I would take 'racialist' to mean is a person who believes in the inherent inferiority of one race of mankind to another, and who acts and speaks in that belief. So the answer to the question of whether I am a racialist is 'no'—unless, perhaps, it is to be a racialist in reverse. I regard many of the peoples in India as being superior in many respects—intellectually, for example, and in other respects—to Europeans."[7]
[7] https://en.wikipedia.org/wiki/Rivers_of_Blood_speech#Politic...
[8] https://mic.com/articles/87359/national-geographic-determine...
[9] For example, it is not uncommon to hear that "racism is prejudice plus power"[10]. That's a great definition if you want a stick to beat people with, but so broad and vague as to be rendered pretty much useless on critical examination. For example, there may be plenty of prejudice against pedophiles. And it is certainly common for societies to use their collective power (through state force or collective action) to mobilize power against pedophiles. Does that make pedophiles victim of racist discrimination? Of course not, but it sure is included in this broadened definition of racism.
[10] http://edchange.org/multicultural/papers/caleb/racism.html