Some corrections:
Which side is it that promoted open borders with absolutely no consequence for ILLEGALLY entering the country?
Both, actually. There's been little to no action on immigration in decades. And it was Reagan - a republican - who approved an amnesty for illegal immigrants in 1984. Trump managed to turn it into a flashpoint by acting like a tiny fraction of immigrants represent all of them, and made it a key talking point while never really doing that much about it. ***The right may not have done a lot over the years, but they did not actively invite the invasion that we saw over the past 4 years, and ignore the ones that did crash the border. Just look at the numbers.
Is it the left or the right that that has been electing and appointing politicians and prosecutors that promote no cash bail,
Left, mostly ***I would say it is left only.
freeing those already convicted,
Both, as long as they were friends. ***Somewhat, but mostly left.
allowing theft up to $950 without prosecution, down charging crimes from felonies to misdemeanors,
Not sure about the first part, I haven't seen this. But really, this isn't a decision for left/right - these are both decisions made by prosecutors, and those decisions are usually heavily based on workload and probability of a conviction. Plea bargains are extremely common in all jurisdictions. ***Allowing theft of up to $950 was a California thing. Not sure if anywhere else jumped on board, but CA does fancy itself as the leader. Places like LA, NYC, Chicago, Baltimore, CA, NY, IL are all places that had AG's and DA's heavily funded by Soros and all went soft on crime because of systemic racism and associated bullshit. Places like TX and FL take a different approach.
and seldom prosecuting anyone that riot out in the streets?
Well, to be fair, what's the point of prosecuting people who riot or who invade the capitol when the next president is just going to pardon them all anyway? ***I guess that is just the risk that everyone must take, since the president has that authority. I will point out though that the January 6 folks (which is your obvious reference) at least spent time in prison, whereas the vast majority of BLM rioters were not even apprehended. And while damage to the capital was relatively small in value, the BLM riots destroyed billions and billions of both public and private property.