Medicaid recipients in Wisconsin would be required to undergo drug testing and could be limited in how long they can receive benefits under measures proposed Thursday by Gov. Scott Walker, who is positioning himself as a reformer as he eyes a 2016 presidential run. The idea, which Walker first proposed during his re-election campaign, will be included in his state budget released to the Republican-controlled Legislature on Feb. 3. Walker announced for the first time Thursday that the plan would apply to childless adults on Medicaid, as well as those applying for or receiving aid from other state benefit programs.