Yes it would be.
The problem is, the republicans don't really have any policies of note, and the ones they do tend to be either very unpopular (hey, lets lock kids in cages and give tax beaks to millionaires!) or lacking in substance (I will protect preexisting conditions! How? Well, I don't know... I just will.)
So, about republicans can do is snipe at Biden, and since Biden has no real major scandals, they have to basically manufacture them.
Why do you think that locking children up in cages is not popular with Americans? You don't know that but you're making assumptions that could be based on human decency.
Locking children up in cages and separating them from their parents without keeping records was meant to scare the migrants so badly that they would give up trying.
Why would that be unpopular with Americans when at least the Trump supporters believe that the immigrants are to blame for their poverty?