Indianapolis, Indiana - Over 20 Republicans in the Indiana state Senate joined Democrats to vote down a plan pushed by President Donald Trump to redraw the state's congressional maps, in a stunning show of defiance.

According to CNN, the vote resulted in 31-19, with 21 Republicans joining 10 Democrats to oppose the measure.

Back in October, Indiana's Republican Governor Mike Braun called a special session to redraw the maps, following in the footsteps of the state of Texas, which made a similar move earlier this year.

President Trump then spent several months vocally supporting the measure, and earlier on Thursday, he shared a social media post issuing a direct threat to Indiana lawmakers who oppose the plan.

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Redrawing maps could potentially help give Republicans a leg up next year during the midterm elections, and secure their control of the federal government.

For Indiana, the GOP currently controls seven of the nine House seats, and redistricting could help the party gain all nine.

In a statement following the vote, Senate President Pro Tem Rodric Bray argued that while state Republicans want to see a majority next year, he doesn't think redistricting is the way to achieve it.

The vote represents one of the most notable – and public – rebukes to Trump from members of his own party. It comes at a time when the 79-year-old's popularity is sagging due to a widespread crisis of affordability, as well as a scandal surrounding the release of documents related to investigations into notorious sex offender Jeffrey Epstein.