The Nevada Legislature’s emergency special session grew contentious Thursday during middle-of-the-night sparring over a proposal to cap tax deductions for mining businesses. The bill passed through the Assembly on a party line vote but fell one vote short of passing in the Senate, where a two-thirds majority is needed to increase taxes. The deduction cap would have provided about $100 million to the state’s general fund and was the first substantial revenue proposal put forth during the nine-day special legislative session.