The top Republican lawmaker in California will propose that his home state be split in two as Governor Gavin Newsom pushes for a Democratic gerrymander in response to Texas, his office says. The creation of “Inland California,” were it somehow to become a reality, would be home to more than 10 million people. 

Assemblyman James Gallagher, who is the leader of the state assembly’s Republican minority, says he will address members of the press on Wednesday about his proposal for a new state. He has been fiercely outspoken about Mr. Newsom’s campaign to gerrymander their state in order to be more favorable to congressional Democrats. 

“Gallagher’s resolution responds to Sacramento’s attempt to permanently redraw California’s congressional maps — an act he says would silence rural voices and rig the political system forever,” Mr. Gallagher’s office said in a statement Tuesday night. 

“The people of inland California have been overlooked for too long,” Mr. Gallagher says. “It’s time for a two state solution.” 

Mr. Gallagher’s dream of a new, more conservative state would include every inland county, stretching from the California-Oregon border to the state’s borders with Arizona and Mexico. 

The other state would include every county that touches the Pacific Ocean, along with a handful of others in the liberal San Francisco Bay area. 

Mr. Gallagher’s office says he will be joined by fellow Republicans in the state legislature for his press conference on Wednesday. 

Mr. Newsom and Sacramento Democrats are plowing ahead with their campaign to redraw congressional district lines mid-decade, which is rarely done. They are doing so after the Texas GOP made the decision to more heavily gerrymander their own state and pick off five heavily Democratic seats in order to turn them into new districts that were carried by President Trump last year. 

Californians will go to the polls in November to vote on whether their state’s independent redistricting commission should be forced to hand map-drawing powers to the legislature through 2030. 

“Don’t p— on my boots and tell me it’s raining. These are rigged maps drawn in secret to give Democrat politicians more power by dismantling the independent commission Californians created,” Mr. Gallagher said in a statement earlier this month. “These maps shred the fair, transparent process voters demanded.”

Were this somehow to become a reality, the creation of “Inland California” would mark the first time in more than 160 years that one state has split into two. The last time it happened was in 1863, when what is now West Virginia broke off from the Old Dominion due to its opposition to seceding from the Union. 

The only way for California to break into two states as Mr. Gallagher desires would be for both the state legislature and the United States Congress to consent to his demands, which is nearly guaranteed to not happen any time in the near future.