What was the incentive for Nebraska to start splitting their electoral votes? It looks like it first began in 1996. Was one party or the other more interested in it?
Apparently it was because it was believed that campaigns would pay more attention, and recalled the 1968 primary with Bobby Kennedy.
Robert Kennedy and the 1968 Nebraska campaign trailAt the time, there were only about a dozen primaries and May 13 was a relatively early primary. West Virginia was the same day, but was not a preferential primary nor was Ohio a week earlier.
1968 Democratic Party presidential primaries (Wikipedia)LBJ had withdrawn, and Humphrey was not running in the primaries. McCarthy was gaining in momentum, and Kennedy needed to cut into his popular support. If HHH was nominated in Chicago without running in the primaries there would probably be riots and Nixon would be elected.
(Youtube)The elector change was proposed by a Democrat, and backed by those who wanted more attention by politicians. Trump did hold a campaign rally a week before the election.
Incidentally, the original proposal in Maine was to divide the state into four electoral districts, which was the normal scheme for states with district election of electors. Feel free to draw a 5-district Nebraska.