Webster's Second Reply to Hayne

[Amy L.]

Dear Symposium,

One thing I've seen referenced again and again, is 'Webster's Second Reply to Hayne,' so I finally tracked it down.

Might someone help me interpret the quote below, as it relates to Kentucky?

"I said, only, that it was highly wise and useful, in legislating for the Northwestern country while it was yet a wilderness, to prohibit the introduction of slaves; and I added, that I presumed there was no reflecting and intelligent person, in the neighboring State of Kentucky who would doubt that, if the same prohibition had been extended, at the same early period, over that commonwealth, her strength and population would, at this day, have been far greater than they are. If these opinions be thought doubtful, they are nevertheless, I trust, neither extraordinary nor disrespectful. They attack nobody and menace nobody."

Webster was saying:
1. KY lost population and tax-base because the slave-industry was difficult to compete with? (Perhaps both when trading in the local market, and purchasing arable land?),
2. With lost population KY had less Congressional representation. (but they had that lucky 3/5 clause)
Or was he inferring something else?

Thanks!