There are two problems with background checks:
(1) We currently value patient privacy more highly than our ability to keep guns out of the hands of the mentally ill; therefore, mental illness data is frequently not included in the database. The resulting background checks are therefore inherently incomplete and flawed.
(2) Although the form itself states that straw purchases are a felony, government officials as high as the vice president have stated publicly that such violations are not being prosecuted.
Until those problems are solved - in other words, until current laws are adequately enforced - expanding the number of transactions that require background checks is just a way to generate more paper, and should not be considered.