Whilst Lincoln undoubtedly was virtually preternaturally strong in his youth, between the rather sedentary nature of his office as well as the President's galloping episodes of depression and his rather glaring physical decline from the First Inauguration onwards, I'm not sure he would have been able to have overcome the rather theatrical, intense Booth.
Now, had Mrs. Lincoln been in the midst of one of her infamous tantrums and swatted the gun out of his hand with her fan before he was able to fire the shot, that would have been an interesting turn.