A vital question: Why weren't liberals and leftists clamoring to tear down statues when Obama was in the White House? 
We can answer for this site.
We were calling out racists monuments even before Barack Obama became president.
For example, from Ava and C.I.'s "TV: The Surreal Life stages comeback!," published January 13, 2008:
Obama denies a lot. For instance, that debate, YouTube/CNN, took place at South Carolina's Citadel and we wonder how many are aware that the institution's history, it's very creation, resulted from the desire to enforce slavery? In a society really concerned with racism, Democrats holding a 'debate' there would have been called out in real time (and we did call it out in real time). But the media creation of Bambi doesn't exist to explore race let alone the racial tensions in so much of today's United States.
Did anyone else object?
No, they didn't say a word.
Certainly Chelsea, Hillary and Bill Clinton were all silent.
Equally true, so were a ton of news outlets who are supposed to report basic facts.