Question on renting when the landlord has multiple applications

[Hari Sarvotama]

I applied for renting a home and paid $80 for background check through an Agent. The Agent confirmed that there are no other applications that time. Looks like, another applicant also applied and they also paid for background check. Now the landlord tells me that both applications are under consideration and he has to reject one. My questions are:

1. Is it legal for the landlord to accept second application when I have paid for background check?

2.The future landlord does not have any reason to reject since we have clean background. In multiple application scenerio, on what legal basis the Landlord can reject an Applicant? Can they reject on basis that the other applicant has offered to pay more? Is it legal?

Thanks