I hear this every so often, but it seldom comes with a citation
This is just one way of saying Obama was actually tougher on immigration than it is commonly assumed. Indeed, Obama earned the name deporter-in-chief from the Left.
Why did he do that? Probably to cover his ass with moderate-conservatives who wanted even tougher action. I don’t see Obama as being genuinely motivated by cruelty on the border and it was never a part of his political brand.
Trump? Totally different story: We know how much he railed against illegal immigrants on the campaign trail and how much that was catnip to his base. Once President, the Trump Administration escalated the scale and scope of brutality on the border. As far as I know the policy of forced family separations was a new one.
Read more here. https://www.splcenter.org/news/2020/06/17/family-separation-under-trump-administration-timeline