Yes, of course they could. You have to understand what cloning is - it's just another way to make a baby. If I wanted to clone you, for instance, here are the basic steps: 1) I would gather a few cells from you (I only need one good one, and I could theoretically get one without even touching you, for instance by taking it off the rim of a glass or cup you drank out of). 2) I would obtain a human egg cell from a donor. 3) I would remove the egg cell's nucleus and insert the nucleus of your cell in its place. 3) After watching this altered egg cell divide a few times to make sure it is healthy, I would put it into the uterus of a surrogate mother. 4) Nine months later, the surrogate mom would give birth to a baby who is genetically identical to you, this baby is also known as your clone. The clone would be a separate human being, and would be just like any other baby...it would just happen to have the same DNA as you do.
Consequently, a human clone could reproduce just like anyone else - UNLESS the person whose DNA the clone received had some genetic condition that rendered them unable to create offspring.