Updated: 5:51 p.m.The National Republican Congressional Committee on Tuesday added more than $2 million in television ad reservations in four Democratic-held districts that are increasingly viewed as vulnerable. The new targets are Pennsylvania Rep. Patrick Murphy, Oregon Rep. Kurt Schrader (above) and Arizona Reps. Ann Kirkpatrick and Harry Mitchell.The move comes as two internal Republican polls provided exclusively to Roll Call showed further evidence of the political peril that Kirkpatrick and Mitchell could be in.The 1st district survey found Kirkpatrick in a dead heat with Republican Paul Gosar. They are tied at 43 percent, with 14 percent of respondents undecided in the Moore Information poll of 412 likely voters taken Aug. 30-31. It had a 5-point margin of error.In the 5th district poll, Mitchell trailed David Schweikert, his 2008 opponent, 46 percent to 38 percent. National Research Inc. surveyed 400 likely voters from Aug. 31 to Sept. 2, with a 4.9-point margin of error.The polls were paid for jointly by the campaigns and the NRCC. The results, along with the NRCCs commitment of resources, confirms the GOPs increasing confidence in Arizona opportunities as the party aims for the majority. Republicans could gain as many as three seats in Arizona this fall. The party is also targeting Rep. Gabrielle Giffords, who is facing a stiff challenge from Iraq War veteran Jesse Kelly, in the Tucson-based 8th district.The $2,022,000 worth of air time that the NRCC has reserved in the four districts in Arizona, Pennsylvania and Oregon adds to the $22 million that it had already reserved in 41 other districts.Expect Republicans to continue to capitalize on emerging opportunities as the playing field expands, said a GOP strategist familiar with the effort. The poll numbers are getting worse for Democrats by the day, and as a result, the chorus of forsaken Democrat incumbents cursing the DCCCs name will only continue to grow louder.The Democratic Congressional Campaign Committee has committed a total of $49 million in 60 districts, including the three Arizona districts and Schraders Oregon district.All four of the Democrats who were added to the NRCCs list of targeted districts Tuesday have substantial cash advantages over their Republican opponents. DCCC spokesman Ryan Rudominer said that given the Republican candidates, its no wonder the NRCC is planning more false attacks against our battle-tested members.The fact remains, given its limited resources, the NRCC is now stuck having to make tough decisions about which of their many flawed candidates with anemic fundraising have disqualified themselves as viable candidates and have to be abandoned, he added.