Key Nebraska Republican Rejects Trump’s Push to Shake Up Electoral Map

The Nebraska state senator who Republicans hoped would help ease former President Donald J. Trump’s path to the White House by agreeing to change how the state allocates its Electoral College votes said on Monday that he would not do so, ending a brief but intense lobbying effort from allies of Mr. Trump and Vice President Kamala Harris.

The state legislator, Mike McDonnell, a Democrat turned Republican from Omaha, said that he would not agree to change Nebraska’s 32-year tradition of awarding three of the state’s five electoral votes by congressional district to a winner-take-all system based on the statewide popular vote, bucking calls from Nebraska’s governor and its congressional delegation to help Mr. Trump.

“In recent weeks, a conversation around whether to change how we allocate our Electoral College votes has returned to the forefront,” Mr. McDonnell said in a statement on Monday. “I respect the desire of some of my colleagues to have this discussion, and I have taken time to listen carefully to Nebraskans and national leaders on both sides of the issue. After deep consideration, it is clear to me that right now, 43 days from Election Day, is not the moment to make this change.”

Mr. McDonnell said he had told the state’s Republican governor, Jim Pillen, that “I will not change my long-held position and will oppose any attempted changes to our Electoral College system before the 2024 election.” He said he had proposed seeking a constitutional amendment next year, which would require a statewide vote to change how Nebraska allocates its electoral votes.

Nebraska is a reliably red state, and, had the change taken effect, it would have affected only the electoral vote awarded from the congressional district that includes