Writing to politicans is your best bet. I've written to local County executive, local mayor, state rep, state senator, US rep, Bud 'PorkBelly' Shuster, US senator, DOJ, DOT, state governor. All addreseses can be relatively easily found on websites such as
www.senate.gov www.house.gov www.doj.gov www.dot.gov
and your state's website

I've gotten replies from everyone except Mr. Porkbelly, including some non-form letters and phone calls. I doubt it'll make a difference, but at least I know I tried! (The best letter is the one who details good reasons to oppose the merger -- I sent two -- first three pages long, another five!)