The US Digital Service started with healthcare.gov, but nowadays they work across the government on projects that matter to people all over the political spectrum: VA, immigration, department of education, and more.
That said, I have no way to predict who the Republican nominee will be or what they'll do. I think the impact of USDS relative to its budget is huge, and I'd like to believe making the government competent at writing software is a bipartisan issue, so I would hope this initiative crosses over into the next administration, whoever it is.
Right now, I think everybody at USDS is just focused on getting results over the next 18 months.