The USCIS Director was also quite clear that a pathway to citizenship for certain undocumented residents would be part of the necessary reforms and that USCIS is preparing for what that might entail in terms of budgetary requirements:

We are preparing for what comprehensive immigration reform might entail. And our preparatory efforts are the very same efforts that we would undertake to achieve greatest efficiency as an agency. And so we have the ability, for example, to accept certain biometric information of 6 million people in a year in our 140 or so application support centers throughout the country. We are developing a nimbleness that, should we need to address or capture biometrics of a greater-sized population of people, we are able to do so. So our efforts are well under way.
That should answer any concerns from the general public and immigration-restrictionists such as Kris Kobach on whether USCIS can handle the processing 'a flood of petitions.' In the past two years, USCIS has reduced service processing times from 12 months to 4.5 months and clearly needs more funding and support from Congress in order to become more efficient.