Mitch Daniels is not a very well known candidate right now, he doesn't have name recognition and he hasn't been actively campaigning as much as some other candidates with similar credentials (such as Tim Pawlenty).

He also has the major problem in that he is short.

One way to look at Republican politics is to break it down until how do Republican presidential candidates communicate to their core constituents. What do they bring to the table in experience, and how do they communicate their vision. The republican party has two different type of wings to this communication.

The "managerial" wing of the republican party and "blue collar" wing of the republican party. The "managerial wing" is the wing that communicates success, efficiency, urban; while the "blue collar" wing is more about populism, values, culture, trust.

Here are the current candidates and they way they communicate

Managerial Wing
Mitt Romney
John Huntsman (which will probably not run)
Mitch Daniels (which may run and is looking more alive than John Huntsman)

Blue Collar Wing
Sarah Palin
Donald Trump
Mike Huckabee
Rick Sanatorium

The person who can fall in both camps is
Tim Pawlenty

Now Republicans do much better electorally if they have a candidate who falls in both camps, due to the fact they can get good turn out and if they have a candidate who can speak both languages they get good results with the indepedents. The Republicans with Bush had a person who could speak to Blue Collar issues but was horrible speaking about the Managerial wing, they were supposed to have a candidate in 2008 who could speak to both bases with George Allen, but he made that racist comment (debatable) in 06 and he lost his senate re-election and thus he didn't won in 08.