Did the lobbyists on staff with Senator John McCain's presidential campaign combine with some well-placed campaign contributions to convince the Senator to back Airbus for a lucrative Pentagon contract over U.S.-based Boeing?  Public Campaign Action Fund's Campaign Money Watch project has released a new ad calling attention to McCain's decision, and asking the Senator to rid his staff of lobbyists once and for all.  Read ABC's coverage of the ad here, which also includes mention of the letter Campaign Money Watch is sending to the Federal Election Commission today.  The letter calls for an investigation into suspicious donations made to McCain's campaign, tied to the Airbus deal:The group is also asking the Federal Election Commission to investigate two other public reports that touch on McCain's connections to lobbyists: That a lobbying company, the Loeffler Group LLP, made payments this year to McCain's national finance director, Susan Nelson; and that a company controlled in part by campaign manager Rick Davis sliced more than $100,000 off of McCain campaign's tab, when the campaign was starved for cash last year. While working for Loeffler, Nelson lobbied on behalf of Airbus. Newsweek reported last month that Nelson was rehired early this year as a consultant for the company, while on the McCain campaign's payroll.  Campaign Money Watch alleges that the payments made by the Loeffler Group and the discount arranged by the company 3eDC could amount to illegal corporate contributions, according to an FEC complaint to be filed Monday.Further coverage of the ad and the FEC complaint from the Associated Press, Los Angeles Times, and the Baltimore Sun.