Sometimes there is just too much space between the edge of the slide and the bullet character that PowerPoint uses.
However, luckily, there is a way to fix the problem and to make the space smaller. Start by displaying the ruler by choosign View, Ruler. Then select the text to alter and, on the ruler you’ll see the marker that controls the positioning of the bullet. Drag it with your mouse, if you need to do this in small amounts, hold Control as you do it.
Which is a bit strange really, because in Word, for example, holding Alt is how you get to fine tune spacing.. hmm! well, if nothing else, these crazy mixed up keystrokes keep some of us in business.