Sure you can.
I worked portable for the first 4yrs in this industry and I out cleaned TM's all the time, or so I was often told by my clients. It not that hard since one client told me I had the carpets looking better than the last guy and all I had done to that point was vacuum, prespray and groom!!
One reason you can easily succeed is that your expenses will be way lower. You won't have a $600 or in more cases $1500/mth payment to even worry about. Maintenance is also much easier and less expensive.
Buy the best porty you can. Maybe check with Les, he and Odin seem to have a cool looking machine going.
Don't use any more than 2 power cords. Its tough enough finding 2 circuits let alone more!
As was already mentioned, market to places where TM's can't go. You've just eliminated 90% of the cleaners in the YP.
I see you're in West Palm Beach. Got to be lots of million $ condo buildings! market ONLY to those and at a higher price than 95% of the other cleaners in the area, maybe even go higher than the highest TM operation. The idea is that you have a highly specialized machine that will provide the best cleaning for their carpets. If it were me and in condo's that cost over $500,000, I'd price about 60-75cents/sf- JUST THE CLEANING. So you can only do one job a day. 500sf just made you $375, with half the overhead! Add protector at half the price of the cleaning, you've added another 187.5 for a $562.5 day. Very respectable!
Sell the "specialized machine", TM's may clean better but so what, they can't reach!
Also sell the security and safety, no hoses over a balcony, no hoses down the hall or staircase, and more importantly, esp in this world, NO OPEN DOORS. Condo owners are getting more and more ansy about security and open doors.
Have a fan/airpath, something to speed dry the carpets.
Have a large dolly or cart, put your porty and all your equipment on that and wheel it on up. You could even make a powered cart, like the Prowler portable machine.
You could have that set up so that you are blowing minds before you even get to the front door.
Oh, market yourself to the best TM operators in town. If you haven't noticed TM operators like speed and almost detest porty work. Make a deal with a couple guys, they give you porty work and you'll pass on house work.
If I knew back then what I know now, I would have remained a porty operator and gone after condos not houses.