What Is the Fudge Factor?

The prevailing view of the universe was that it was static. We didn't see anything moving. Hubble used this really cool observation by another astronomer Henrietta Levitt who discovered a certain kind of star called Cephids. These are a particular kind of star and you can use a trick to tell how far away they are just by looking at the light from them. That was the first clue that actually the universe is expanding. But why did Einstein feel like he needed to add a fudge factor to make the universe static? Couldn't the universe be on its way to crunching down into a black hole?