Republican leaders announced on Thursday that legislation to build a wall along the Mexican border will cost between $12 billion and $15 billion. It's not yet clear how the massively expensive project from the conservative party will be possible without adding to federal deficits. House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell could not answer that question when asked on Thursday. The wall has been one of President Trump's main goals since he entered the political arena. The wall, according to Trump, will be paid for by taxpayers until Mexico reimburses the U.S. for the project. Mexican leaders vocally oppose the wall and have repeatedly said they will not finance it.