Complex sentence: Because Goldwater had done well in the Deep South, delegates to the 1968 Republican National Convention would be more Southern and conservative than past conventions; there was a real possibility that the conservative Reagan would be nominated if there was no victor on the first ballot.
Split into simpler sentences: Because Goldwater had done well in the Deep South, delegates to the 1968 Republican National Convention would be more Southern and conservative than past conventions. There was a real possibility that the conservative Reagan would be nominated if there was no victor on the first ballot.