Maybe. But on a more positive note, it has also distracted the media from covering any Republican candidate who isn't Cruz or Trump.
I think that is a very good development for those who are supporting either Cruz or Trump.
DISCLOSURE: I am a Cruz supporter, but will vote for Trump if he wins the nomination. I won't vote for any other candidate (not that it matters anyway, since my state will go for Hillary or Bernie no matter what the rest of the country does.)
But I don't see this as helping Cruz. It may not hurt him. But he spent more than a week in the weeds (yes, in policy weeds) with Rubio over who did what on the Gang of Eight bill.
Again, I'm a Trump guy, but Cruz by getting into this stuff continually looks like someone playing small ball while Trump has the "big picture" issues. If I was Cruz's manager I'd be doing the biggest-vision things I could and refuse to comment on Rubio or the birth issue.