You could, but we don’t recommend it. For best results, the talent (presenter) should be positioned at least 10 ft away from the camera. Otherwise, viewers will detect left to right eye movement as you read each line of text. Most webcams have a fixed focal length (ie no optical zoom), so if you are correctly positioned the shot framing will probably be less than optimal.
The good news is that if you have a smartphone, you can use a lens adapter like this one to add optical zoom functionality to your phone’s HD camera.