I’m Catholic, so don’t look to me as the Pope of Prebyterianism.
However, I looked at some of their orders of liturgy (what they do when they’re in church), and there is a separate confessional rite prior to the communion rite where they pray that they confess personal sin and corporate sin.
As a Catholic who is close to evangelicalism (I have often prayed and socialized with evangelicals), I would say that the experience of being convicted of one’s own sins by the Holy Spirit is an essential part of evangelicalism (and for most serious Catholics, as well). The natural response of being convicted of sin by the Holy Spirit is to seek forgiveness. From the Lord, it is freely given.
Then the various talking heads would spend days discussing how Trump is a sinner and he admitted it. They would go into detail about what ever sin he confessed to.
Normally, I would consider the last two sentences I just wrote as tinfoil hat material, but this is not a 'normal' time in our country.
Anyway, the answer Trump gave removed their ability to try and delve deeper into his personal life in an attempt to find a chink in the armor.
I find the act of asking him if he ever asked for forgiveness to be very rude and very unprofessional. That is nobody else's business. I noticed they have not asked any other candidate the same question.