The Python-2.7.9 version of the Windows-x86 MSI installed version works fine with the 32-bit mingw. In fact I rolled back to that release and built my code successfully.

Somehow the fix for https://bugs.python.org/issue23199 must have broken the 32-bit libpython27.a.

In fact, just tried running the commands in the comments to that previous bug report by hand which produces a similarly broken 32-bit libpython27.a.

   x86_64-w64-mingw32-dlltool --dllname python27.dll --def mingwlib.def --output-lib win32\libpython27.a -m i386

This creates an archive with two 64-bit object files. However the following builds a correct import library with all 32-bit objects.

   i686-w64-mingw32-dlltool --dllname python27.dll --def mingwlib.def --output-lib win32\libpython27.a -m i386