Seems to me that Romney won the immigration-policy exchange with Gingrich, whose really couldn’t explain his charge about deporting grandmothers. But Romney’s flash of anger at being called “anti-immigration,” while effective in this case, must be used sparingly. If he takes that kind of offense at every barb from Gingrich, it will be a turnoff. Voters want strong and confident. They don’t want thin-skinned.