Daniels has another reason to court social conservatives: In 2010, he made a controversial statement about Republicans needing to "call a truce on social issues" and focus on economic matters. For many social conservatives, this raised a red flag.
Though Daniels made the remark a year ago, it hasn't been forgotten. Daniels did not participate in the May 5th debate, but that didn't stop the moderators from asking a question about it. (Santorum was given the question, and he took the opportunity to make an impassioned attack against the idea of such a "truce.")
For unknown candidates like Daniels, the media usually latch onto one or two details and repeat them over and over. This influences the reporting, political commentators' commentary, and even the questions a candidate receives at a debate. A good example of this is how the media treated Mike Huckabee during the 2008 campaign: Because he had been a Baptist preacher (years before he was the two-term governor of Arkansas), he received endless debate questions about religion. One can already see the two bullet points being written about some of the present candidates: Cain is black and used to run Godfather's Pizza, Santorum is a social conservative, Pawlenty is boring, etc.
Another reason Daniels' suggestion of a "truce" will harm him is that Republican primary voters are concerned--perhaps to the point of paranoia--about a "fake" conservative ("RINO") winning the nomination. For the social conservatives in Iowa, a Republican who doesn't seem to care about social issues would fairly be classified as a RINO.
As observed in Daniels' Profile and the Rankings page, Daniels' path to victory is through Iowa, after being selected as a "consensus candidate." Daniels is unlikely to win by being the most exciting or inspiring candidate; his best chance is to avoid being unacceptable to any faction of the Party. Daniels cannot afford to alienate anyone, especially not in Iowa.
Daniels has made an important step toward placating social conservatives. Daniels will also benefit from free (and badly needed) publicity if the news media do a lot of reporting on the anti-abortion legislation. This will not be the last time he is called to account for the "truce" gaffe, but it seems Daniels is on the right strategic track. Elephant Watcher calculates Daniels has a 5% chance of winning the nomination.