It occurred to me that the Democratic primary is a classic study in machine v. grassroots politics.

Obama has put together an impressive grassroots movement. Clinton has cranked up the formidable Clinton machine to keep it competitive.

With only a few exceptions, Clinton has done well in big states with established Democratic political machines. Obama has done well in smaller states where Obamanauts can go door to door selling retail.

The trouble is, grassroots campaigns may win a few battles but machine politics usually wins the war, like a big old Bush Hog rolling over an overgrown weed patch.

In 2004, the Republicans had a bigger Bush Hog. In 2008, ours is stalled in the tall weeds and will need extensive repairs before November.