I agree wholeheartedly with this New York Times editorial:

The Federal Election Commission — the supposed referee of fair campaigning — has just created an ethics loophole big enough for lobbyists to fly a corporate jet through. The commission has taken upon itself to reverse the Senate’s self-restriction against lawmakers’ cozy cut-rate travels on corporate jets.

The planes were long provided on demand from favor-seeking executives and lobbyists intent on private time with lawmakers. But, two years after the Jack Abramoff corruption scandals, the Senate banned the practice of paying a mere single-seat rate for commandeering their friendly exec’s company plane. It mandated that members pay the full (prohibitive) charter rate, as if renting the whole plane themselves. This targeted an abuse by which corporations provided jets to grateful lawmakers to dash about on political errands at token prices. (The House went the Senate one better with an outright ban on flying on noncommercial aircraft.)

The F.E.C. gutted the reform by totally misinterpreting it to say it does not apply when a senator is traveling on behalf of assorted party committees and not as “a candidate” himself. This is nonsense by any fair reading of the Senate’s rule, which clearly considers any incumbent an ongoing candidate 24/7, regardless of announced business in hopping a corporate jet.