It's official! Scott Walker Ends Presidential Campaign

Good riddance! Two down, 215 to go...

As for WHY he dropped out: Scott Walker: What Went Wrong? And this is from the decidedly conservative National Review. Among their conclusions:
Quote
Walker’s rise came so early that he didn’t yet have a campaign in place and hadn’t fully studied up on national issues, and it showed. His Iowa bounce played into a key strategic decision to make the Hawkeye State central to his campaign, and relatedly, to compete directly for the Right of the party, which for him required changes in tone and position. Walker is a conservative but not a fire-breather. That made his attempt to straddle the grassroots and the establishment — which would have been difficult for any politician — harder to pull off.
Above all, the past few months have amplified questions about whether Walker’s campaign and, more importantly, the candidate himself are built to thrive on a stage larger and less forgiving than Wisconsin. Political observers had long worried about whether he had the charisma to succeed in a presidential contest. Now, there are doubts about his substance. At times, the candidate and his operation have appeared accident-prone and politically immature.

A well reasoned argument is like a diamond: impervious to corruption and crystal clear - and infinitely rarer.

Here, as elsewhere, people are outraged at what feels like a rigged game -- an economy that won't respond, a democracy that won't listen, and a financial sector that holds all the cards. - Robert Reich