Carl also supports him and gives some good reasons. His reasons are not the same as mine, but we do come to the same conclusion.
While talking to a good friend about Feiglin's support, it occurred to me that if Feiglin does "too well," the chances are that Bibi will most probably invite back some of the former Likud MK's, who had deserted to Kadima. That will strengthen him and gives the turncoats a chance to keep their seats.
The big problem with Feiglin is that he has been working too superficially within the Likud, focusing on elections. He thinks as an outsider. To take over the party, he must work from the bottom up. He has to take over the party institutions and internal positions. He should have been convincing old time Likudniks, who think of themselves as from Cherut or Gachal, that he's one of them.
I'm supporting Feiglin, because I think that Bibi* will endanger the country, because he's too much like Barak and Olmert (and Sharansky) in his policies. They all promote, support giving the Arabs our land. Bibi and Sharansky attach it to "conditions," but it's all the same. Whether the Arabs call themselves "modern, western democrats" or just plain terrorist anarchists, they still want to destroy the State of Israel. That's the bottom line.
When you're buying something expensive, you need to know the final price, not the base price without taxes and surcharges.
*Yes, there's a third candidate, Danny Danon. I've checked with sources who've worked with him, and they all say that he's an unreliable opportunist, like a young Olmert, but worse, since Olmert was better in his youth.