For obvious reasons, mainly votes.

Via Politico:

President Obama said there is one thing he absolutely won’t compromise on in immigration reform: a pathway to citizenship. But as for what he would be willing to give up, he won’t say.

“It wouldn’t be very smart for me to say right away what I know I’m not going to get,” he said in an interview with Univision Friday. “What we’ll do is continue to work with senators from both parties to try and get the Senate bill passed.”

The president praised the bill produced by the Gang of Eight as a “good piece of work” that doesn’t include everything Obama would have wanted but stiil meets his “core requirements,” which include provisions to crack down on companies who hire illegal immigrants, streamline legal immigration, and strengthen border security as well as to create the pathway.