Senator McCaskill? Your Vote Today?

I could hardly believe what I read today about our Missouri Senator Claire McCaskill and her vote on the Farm Bill:
Which Democrats Just Voted against Food Stamp Funding?
From this article at The Daily Kos (bolding added for emphasis): The Senate began its process of amending the farm bill this afternoon.  Fom what I can tell from the Senate website, as of now, three amendments have received a vote so far:
--Sen. Maria Cantwell's (D-WA) amendment "to allow Indian tribes to participate in certain soil and water conservation programs"passed 87-8.  The eight "No" votes were all Republicans: John Cornyn (TX), Ted Cruz (TX), Ron Johnson (R-WI), Mark Kirk (R-IL), Mike Lee (R-WY), Rand Paul (R-KY), Marco Rubio (R-FL), and Pat Toomey (R-PA). --Sen. Pat Roberts's (R-KS) amendment to cut an additional $12 billion from the supplemental food assistance program (SNAP, or food stamps) failed 58-40.  Three Republicans broke party lines against it:  Susan Collins (ME), Lisa Murkowski (AK), and Roger Wicker (MS). --However, the amendment on which I would like to focus attention here is that of Sen. Kirsten Gillibrand (D-NY).  Gillibrand proposed to restore the $4 billion that the current farm bill--designed by Debbie Stabenow (D-MI) and Thad Cochran (R-MS)--cuts from SNAP (Supplemental Food Assistance, known as food stamps--as I indicated above) and to offset this restored funding with a limitation on crop insurance reimbursements. Our current crop insurance subsidies benefit large farms at the expense of smaller ones and are one of the many glaring manifestations of corporate welfare that Congress never fixes.  Gillibrand's amendment would, in essence, cut corporate welfare spending to restore social welfare spending.  Did this progressive proposal pass?  Not even close.  It failed 26-70:  not even a majority of Democrats voted for it. Which Democrats voted against restoring food stamps--voting against veterans, children, seniors, and struggling to get by? And that's when we find out that yes, as a matter of fact, our own Senator McCaskill voted against it. I'm not saying absolutely here that she and all the Democrats who voted against it shouldn't have, necessarily.  I'd just like a good, intelligent, honest answer why they did. This seems as thought it was a vote FOR the common worker AND would have been against corporate welfare. What was not to like?