The article you cite does not say the Obama Administration actively sought to find denaturalizable citizens, it says that an error which would have made citizens denaturalizable was discovered late in the Obama Administration, and a recommendation was made to identify all the effected persons and decide what course of action to take.

Yes, every Administration has reacted to discovery of information which would have made citizens denaturalizable, sometimes by pursuing denaturalization. Since the second Red Scare, however, the government has actively and specifically sought to find bases for denaturalization as a policy goal.

Despite the poor media framing, Trump's "task force" is a response to that same fingerprinting snafu, and is predicated on the suspicion that some of these naturalized citizenships were improvidently granted.

https://www.theroot.com/trump-creates-denaturalization-task-...

From CNN:

> Since the Obama administration, Immigration and Customs Enforcement has also been working to put more than 300,000 fingerprint records into a system that can be checked against citizenship applications.

> According to USCIS, the effort to followup on those records has resulted in 2,500 cases that have been flagged for in-depth review, and 95 of those have been referred to the Justice Department to date.

Yes, I get that Trump's a big scary monster, but despite the media charade, and his inartful presentation, this seems to be exactly an extension of what the Obama administration did.