Donald Trump believes he will win four electoral votes from Nebraska, but it’s the fifth one that he is increasingly fretting about – leading the former president and his Republican allies to mount a last-ditch effort to try and change state election law only weeks before ballots are cast.

A single Republican state senator appears to be holding back a push by Donald J. Trump to net a potentially pivotal electoral vote even before ballots are cast.

Republicans in Nebraska are trying to change a critical part of the state’s electoral process, which could have significant effects on the presidential election. The change, a switch from a system that awards electoral votes by congressional districts to a more traditional winner-take-all system,