A great-grandparent or even a great-great grandparent from Italy used to be all it took to guarantee Italian citizenship. A surprise decree has now changed all that, making it much harder for those with Italian ancestry to use blood line as a pathway to become Italian.
On March 28, the Italian government tightened regulations for claiming citizenship by jus sanguinis, or descendent blood line, effective immediately.
Basically you now need an Italian parent or a grandparent who was born in Italy, or an Italian parent who lived in Italy for at least two years before you were born, to be eligible. This is a major change to the citizenship law, and caught everyone by surprise.
Everyone, the article explains the situation very well.
The government's stance is otherwise normal (reasonable is too strong a term here). Basically, the 2 year old was technically not deported - but in light of not separating families from their children, the 2 year old was sent with the mom at her request.
A Trump-appointed judge was very skeptical of this however, since the father is still in the US and was asking to take custody of the child, so the judge reasonably wanted to double check with the mom that the mom really was ok with keeping the 2 year old with her. Only double checking wasn't possible because the mom was supposedly already released to another country and outside ICE custody - even though the plane was still in the air according to flight tracking information for that time.
Apparently ICE also tried to deport the father once he started complaining. The status of the father isn't clear at this point but I would not be surprised if - in a parallel to the case of Kilmer Abrego Garcia - the parents turn out be a US Citizen + unregularized pair.