In other words, they are fighting the wrong people.  The Left has been using blacks for half a century.  Some do it out of malice (think: Clinton, Obama, etc. who abuse the poor to gain more power), some out of ignorance (think: bleeding hearts who like to sooth their consciences by giving away your money and rights) and some for both reasons. Here are a few examples of how the Left harms blacks.

1. Illegal aliens take the jobs and/or suppress the wages of low income blacks. This is a simple and indisputable impact of the law of supply and demand.  Leftists love illegal aliens pouring into this country because it is an easy way for them to buy votes.
2. Abortion kills blacks at a rate over three times that of whites, and the Left’s dream of taxpayer-funded abortions will take that even higher.  If literally taking the lives of innocent black children in this way doesn’t enrage BLM, then they are ignorant or complicit.
3. Leftist government, education, media and entertainment continue to encourage out-of-wedlock sex and single parenting, which inevitably leads to poverty, crime and prison.  This happens regardless of race but happens more in black communities because of how the Left targets them with their welfare programs.
4. Minimum wage policies will take away even more low-income jobs.  These jobs were never designed to support families.  Minimum skills will always yield minimum wages.  But these artificial, un-Constitutional wage increases inevitably cost jobs via automation (at some point a machine will be more cost-effective than a human) or lost hours (see the Leftists at Starbucks who have been mugged by reality).  The real minimum wage is always going to be zero, and more and more minorities are experiencing that thanks to the Left.
5. Fostering racial tensions, especially with the police.  Obama & Co. have done everything possible to start race wars.  They have made poor neighborhoods more dangerous with the “Ferguson Effect,” where police have a drastically reduced incentive to respond quickly or to do any defensive maneuvers.  If you are going to be shot at or called a racist no matter what you do, why not just show up after the bodies are cold and fill out a report?  I feel for the law-abiding people who are slowly entering into anarchy.  But some BLM leaders actually want there to be no police.  What could go wrong?
6. Gun grabbing.  The Left never misses an opportunity to exploit tragedies to try and take the guns of law-abiding people.  It is too bad no one represents the poor but law-abiding people in South Chicago to let them buy guns to legally defend themselves.
7. Out of control schools.  When hoodlums are given a free pass to behave in any way they like in schools and not be kicked out then the good kids suffer.  The Left now considers it racist if minorities are disciplined more often than whites, regardless of the actual infractions.  The social contract to provide education to all children should have a caveat that if you don’t behave well then the parents are responsible.  And as always, the government unions and politicians just take turns giving each other your money instead of helping the children.  Even Leftists like FDR knew those unions should be forbidden.

The Democrats do all these at the expense of low-income blacks, but history shows that the blacks will vote for them anyway.  So why change?

So if you are a conservative and anyone asks what you are doing to help blacks, let them know that you are doing a lot: Fighting abortion that kills blacks at a rate three times that of whites, fighting illegal immigration that take the jobs and/or suppresses the wages of low-income blacks, improving their police protection, fighting for their right of self-defense, fighting minimum wage increases that will take their jobs, and more.