ALL CARS (sans maybe a Smart or Fiat500) are capable of towing at least 1,000 lbs. The Jetta TDI actually has the tow record for a car but I can't remember what the amount was. Something like 3,000 lbs sounds familiar.
When dealing with a boat launch you of course have to deal with the surface being wet, sloped, and many times even algae-invested (very slick).
My pick for SMALLEST (not necessarily cheapest) 2k lb tow vehicle would be a Tiguan actually. It is rated to 2,200 lbs and is really not much bigger than a 4-door Golf...
Subaru Forester is rated to 2,400 lbs with either the 2.5 or the Turbo. Those are cheaper than Tiguans...
Most of the other 'cute-utes' tow less than 2,000 lbs.
Volvo rates their cars quite well for towing;
C30/C70 - 2,000 lbs
S60/S80/XC60/XC70 - 3,300 lbs
XC90 - 5,000 lbs