Electron-argon scattering in the presence of a linearly polarized, low-frequency laser field is studied theoretically. The scattering geometries of interest are small angles where momentum transfer is nearly perpendicular to the field, which is where the Kroll-Watson approximation has the potential to break down. The Floquet R matrix method solves the velocity gauge Schrödinger equation, using a larger reaction volume than previous treatments in order to carefully assess the importance of the long-range polarization potential to the cross section. A comparison of the cross sections calculated with the target potential fully included inside 20 and 100 a.u. shows no appreciable differences, which demonstrates that the long-range interaction cannot account for the high cross sections measured in experiments.