On issues stemming from immigration to health care and foreign policy, the 2020 candidates have been increasingly critical in their public assessments of the Obama administration. And they’ve used opportunities from the debate stage to candidate forums to try and turn Biden’s ties to the former president from an overwhelming asset into something more complicated.

Senator Bernie Sanders’ (I-VT) campaign has used Obama’s own words to challenge Biden’s notion that Obamacare simply needs to be built upon. Senator Kamala Harris (D-CA) challenged Biden over the Obama administration’s deportation policies. Senator Cory Booker (D-N.J.) backed off support for the Obama administration’s 2015 Iran nuclear deal as originally written. And Governor Jay Inslee (D-WA) has attacked Biden for a naivete about dealing with Republicans—in what has been interpreted as an implicit rebuke of Obama’s own failure to fully grasp GOP recalcitrance.

The subtle targeting of Biden has come as Democratic activists and progressives have continued to grapple with the Obama legacy as well. In particular, the Trump administration’s family separation policy and inhumane conditions in detention facilities has sparked a broader conversation among Democratic voters about whether the Obama administration’s own deportation policies laid the groundwork for the current controversies.