When I push the remote, the gate opens about 1 foot and then closes about 6 inches like it hit something.

Depending on the gate opener and how long it has been installed this could be a few things. 

If you gate opener is a battery operated system, ie Mighty Mule, Lift Master, Apollo, Patriot, GTO/PRO - the battery could be worn down and needs to replace. When the battery gets low it will mistake the low voltage for the voltage draw caused by an obstruction.

If it is a direct voltage gate opener - most other brands, then if could need lubrication on the pivot points of the gate opener and the hinges of the gate. (check this if battery is not issue from above)

If it is a new install check the geometry of the rear pivot mounting of the gate opener. If the setback is off the leverage will not be correct and it may be too much force on the motor and making it obstruct.