I'm no racism scholar, so to ensure there's no confusion about how I'm using the term "institutional racism" I am referring to effective racism in results, whether designed as such or not. This diary is to demonstrate the inherent and inescapable racial bias of the filibuster. It only really works for white people. If you are still inclined to defend the notion that the legislative process should have baked-in "minority" protection mechanisms, I won't argue with that here, but you should walk away understanding that the filibuster is a remarkably poor means to such an end given that it can only really be relied upon to protect one kind of "minority" (who aren't even actually a minority - white people).
First Past the Post
The Senate, like most (all?) other elections in America takes the form of candidates vying to represent some defined geographical space, and requiring only a plurality of the votes in order to win. Hence, "first" past the post, with no requirement to attain 50% of the vote, and no mechanism for representing the views of the potential 60% (or even higher in extreme cases) of voters who might have voted for other candidates. America is generally effectively a two party system, so other than a rare independent or celebrity third party candidate, the winner will need something over 48% of the vote to win.
Race Matters in Voting
Proving this and quantifying it is much beyond the scope of my expertise and this diary. Voters have long exhibited a preference for candidates who are racially like them. There are exceptions of course, but you don't get many minority politicians in legislative bodies that do not ensure they have minority-majority districts in their electoral maps. Race isn't the only thing that matters in voting of course, voters cleave along many forms of self-identity, along issues, ideology, economic needs and so forth, but there's no denying race matters.
The Senate Sucks at Minority-Majority Districts
Simply the electoral boundaries are fixed, America is still (and for some time to come) a majority-white country, and there's just very few states with significant enough minority populations to reliably elect many non-white Senators. There have been seven hispanic and six black US Senators in American history. Only three of those black Senators were popularly elected. Black and hispanic are the two largest racial groups other than white in America. There have also been seven Asian senators, however five were from Hawaii, and as Hawaii is the only US state that is majority-minority it is the exception that quite literally proves the general rule.
Let's see the three biggest racial groups by state in maps, taken from here.
The key thing on these maps is to notice the different scales used for the various shadings of blue (sorry, I looked for better maps but couldn't find any). The scale for white starts out much higher than for the other groups, and goes to over 90% in some states. You can see a few states with major Hispanic populations in the south-west, a few states with major black populations in the south-east, but whites are a major group everywhere (even in Hawaii they're hardly insubstantial).
You need 41 Senators To Filibuster
So you're a member of a given minority group. I have suggested racial minorities here, but this works for other kinds of politically salient minorities such as sexual orientation or religion, because similar maps could be drawn showing that heterosexuals and Christians similarly dominate the state level demographic US map. Now try to get to 41 Senators willing to block some measure odious to your minority group but popular with the majority (or plurality). It's going to be pretty difficult for every group except whites, straights and Christians. It's possible that you will get some support by Senators not of your minority group, but assuming they are part of the majority/plurality group pushing the policy you are fighting, they are really swimming upstream electorally to do so. This doesn't tend to happen. It's nice when it does, but when designing systems, you don't rely on lucky breaks to make the thing work. To wit, this is why we see filibusters to block anti-lynching and voting rights laws (filibusters to protect the majority's ability to oppress minorities), but you don't see filibusters blocking the Defense of Marriage Act, defunding ACORN or the authorization for military force in Iraq. Minorities needed protection from abusive bi-partisan majorities those days, and the filibuster was absolutely no help to them.
This is the institutional racism of the filibuster. There is no fix of the filibuster rules which can really fix this. Even if you posited lowering the filibuster threshold to 2 (the current number of Hispanic Senators), you still don't have a minority protection scheme that would currently protect black Americans (who have zero Senators) or gay Americans (who have 1 Senator). Many filibuster reform schemes are in fact suggesting the opposite, by lowering the bar for cloture which only puts the filibuster even further out of reach of any other minority group. If you support this in any recognizable form, you are essentially channeling Henry Ford's dictum about black Model-Ts, "America can have any laws it wants, so long as these laws are ok with white people." The Senate without a filibuster will still be a grossly undemocratic and embarrassingly unrepresentative chamber (yay, 20% women, new all time record!) but that's a much tougher nut to crack given the rigidity of the US constitution in this regard. Still, no reason to exacerbate it by maintaining a special protection rule in an unrepresentative chamber only useful to one group.
The decline in proportion of white people in the US electorate will ameliorate this somewhat, but not very much. As I noted above, under first-past-the-post, you only need a plurality to win, and even as white Americans lose their absolute majority in decades to come, they will remain the largest racial group far past that point. Actually, there is a risk that America becoming a majority-minority nation will exacerbate the use of the filibuster by the white racial plurality - to the extent the non-white groups cleave together (under the Democratic party coalition) and see their interests as aligned (to a significant degree currently), the party of white people (Republicans) will need to block a lot of legislation pushed by the coalition of Everyone Else.
The Good News
America does have a built in systemic mechanism for defending vital minority interests against abuse by the majority, it's called the Bill of Rights. It's not perfect, and enforcement by the Courts is of course irregular, but the wins tend to be durable, and it doesn't require a given minority group to jump through unattainable electoral hoops in order to have any hope of exercising its protection. The afflicted minorities don't even need to have any elected representation of their group. They just take their grievance to the courts.
This is how most other countries considered free societies have also found best to provide minority protections. None have devised anything like the filibuster (in fact none I can think of even has an upper chamber that is equal to, never mind more powerful than their lower house like the US does). This is why the filibuster should be abolished and not reformed. It's fundamentally unjust at an institutional design level.