The good ole Trek hybrid is not going to like the longer haul and I'm going to want something that is less forgiving on bumps, but translates more pedal pushing into forward motion, especially uphill.
Depending on your budget (and size), I'd look at a steel touring bike to take the daily punishment DC commuting is going to dish out. Check out any of the following if you've got around $1,000 to spend:
- Surly CrossCheck
- Surly Long Haul Trucker
- Specialized Tricross
- Bianchi Volpe
- Salsa Casseroll
- Trek 520
I'm biased towards the CrossCheck because I own one and love it, but any of those bikes I listed would work great if you're buying new. Just for size reference - I'm 6'2" ish and weight well over 350lbs and have had minimal problems commuting with about 20lbs of extra weight in laptops and clothes each day.
If you're going to the used route, get any old '80s steel road bike and just get it thorough inspected and tuned up. If you get one that needs a total rebuild so be it, but DO NOT UNDER ANY CIRCUMSTANCES go cheap on your bike or repairs if you're going to be commuting on it daily. I did that earlier this year and regretted it.
Most rewarding part: Zipping past needledicks like me who were stuck in traffic on the TR bridge.
That's me every morning on the 14th Street bridge. I sometimes wonder what's more pathetic - that you paid upwards of $70K for a S-Class Mercedes to sit in traffic for 10+ hours a week to commute to your McMansion or that a total fatass blew past you on the bridge at 25mph.