Should not be an issue as your Canada ETA will be assessed based on Canadas requirements not the US. You should ensure you declare any visa refusals in the ETA application should there be such a question as Canada and the US do share information . Not declaring if asked in the application would be misrepresentation if discovered and could not only lead to a rejection but worst case a ban for a while.
A minor point in that an ETA is not a visa but just gives you authority to board a plane bound for Canada, it is your visa exempt passport that you present to CBSA for entry assessment.
