Republicans may have bit off more than they can chew by making repealing the Affordable Care Act their first priority in 2017, a top White Houser adviser said Tuesday.

Valerie Jarrett, senior adviser to President Obama, said on CNN Republicans are finding out that it’s going to be hard to replace the outgoing president’s signature law. She said the law is built in such a way that repealing unpopular parts of it are inevitably going to take popular parts out too.