If you're working on recording projects on linux, why the heck are you using Audacity? Seriously, save yourself a lot of headaches with Ardour.
Ardour works fine with an Audio Technica AT2100 USB (I tried it and can verify that it uses the standard USB host drivers without complaint) for both I/O and works out-of-the-box with most of my audio interfaces and an XLR mic.
My 2¢: Based on my experience with podcasters, I wouldn't recommend a Snowball for beginners doing spoken-word recordings. This is a "worse is better" scenario where a cheap dynamic will give you better out-of-the-box results than a condenser mic like the Snowball, in part because it forces speakers to get closer to the mic (increasing the ratio of signal to ambient noise), and in part because dynamics usually can't record anything over ~15 kHz (spoken word tops out around 8 kHz).
A Snowball is fine for folks savvy enough to use an EQ to roll off everything over, say, 10 kHz during production.
I alternate between an sE V7 dynamic, a Blue Encore 200 "active dynamic", and an AT2035 at my desk for recordings. The Blue is something I'm just testing but the other two microphones are great for different things. (Anyone who hasn't checked out a sE V7 should; for my money it's the best thing in the "SM58 range" of dynamics, with a really clear sound for a dynamic. And the damned thing won't roll off your desk if you have it handheld...)
You get around this be setting JACK to use the snowball device for capture only (and by doing so you are using its clock) and then attach whatever device you are using for monitoring as a JACK client using zita_j2a from the zita-ajbridge tools package.
I do know that programs like Adobe Audition on Windows offer that in a plug-and-play way.
life changing when I started using that for multitrack recordings..