Trimming won't get it to straighten, but you could put a plant support ring (or make your own with stakes) around it to help hold it up. Flopping in ornamental grasses tends to be caused by soil that is too nutrient-rich and/or lack of a full sun exposure (for sun-loving grasses, which includes this species). Full sun is a minimum of 6-8 hours of direct sun a day in summer.

Miscanthus, the type of ornamental grass this belongs to, is invasive in Maryland, and if you are open to it, we'd suggest removing it and replacing it with another species (either native or non-invasive). Other selections won't have the unique banded/striped look of the clump on the left, but some do come in other variegated (striped) forms or develop color in autumn (like turning burgundy, purplish-pink, or yellow).

Miri