I believe that tufts has a program that guarentees admission, assuming you keep the minimum grades. At least they did 5 years ago.
I did the Bryn Mawr program. Although they do not guarentee a slot, almost everyone gets in. I think only 1 of the 75 people in my year didn't get in. Of course if you don't do the linkage program, you still have to apply.
Ed