The problem was to do this without the loss of conquest and without permitting another general of the same political party to acquire like popularity.

The fact is, the administration of Mr.Polk made every preparation to disgrace Scott, or, to speak more correctly, to drive him to such desperation that he would disgrace himself.
General Scott had opposed conquest by the way of the Rio Grande, Matamoras and Saltillo from the first.

Now that he was in command of all the forces in Mexico, he withdrew from Taylor most of his regular troops and left him only enough volunteers, as he thought, to hold the line then in possession of the invading army.

Indeed Scott did not deem it important to hold anything beyond the Rio Grande, and authorized Taylor to fall back to that line if he chose.

General Taylor protested against the depletion of his army, and his subsequent movement upon Buena Vista would indicate that he did not share the views of his chief in regard to the unimportance of conquest beyond the Rio Grande.
Scott had estimated the men and material that would be required to capture Vera Cruz and to march on the capital of the country, two hundred and sixty miles in the interior.