Complex sentence: The prominent turning point occurred when the right-wing Likud party won for the first time the election of 1977, which by itself was a manifestation of the strengthening of the more extreme Zionist positions.
Split into simpler sentences: The prominent turning point occurred when the right-wing Likud party won the election of 1977 for the first time. This alone was a manifestation of the strengthening of the more extreme Zionist positions.