Yeah. Sure. Some SCOTUS judges introduced the trimester concept into the law -- as though it had been handed down by Moses, and guys like you imagine that it is a meaningful line of demarcation....
Don't care much about what the Judges have to say.
I go by when a fetus becomes self-aware, which any biologist can tell you, happens between 18-24 weeks.
I say the first trimester is a good cutoff, because it leaves some time to spare for any cases of early development.
That's not some kind of arbitrary deadline, it's just fact.
If new data is discovered that disproves that fact, then I will stand up and listen, and change my opinion.
But, since that has not happened, my opinion remains firm. I base my opinion on fact, not faith.