What's her evidence for this lack of "rhetorical-testosterone"? Along with a lot of vague stuff about how Obama is "a chatterbox" who shares with "Ronald Reagan and Bill Clinton" (!) the ability to "assume feminine communication styles effectively", the column includes exactly one relevant fact:
Obama's [oil crisis] speech featured 13 percent passive-voice constructions, the highest level measured in any major presidential address this century, according to the Global Language Monitor, which tracks and analyzes language.
... The first thing to say is that there isn't the slightest evidence that passive-voice constructions are "feminine".
Women don't use the passive voice more than men, and among male writers, number of passive-voice constructions doesn't appear to have any relationship at all to real or perceived manliness. The "passive is girly" prejudice seems to be purely due to the connotations of (other senses of) the term passive, misinterpreted by people who in any case mostly wouldn't recognize the grammatical passive voice if it bit them on the leg. ...
I don't have time this morning to try to figure out how Mr. Payack [of the Global Language Monitor] derived his passive percentages, if any information about this is available I'll have more to say when I've looked into this further. But I did just make a quick analysis of president George W. Bush's post-Katrina address to the nation. I count 142 sentences, 25 of which contained one or more passive-voice tensed verb constructions. That's 17.6%. Doing the same thing with Barack Obama's post-oil-spill address, I count 135 sentences, 15 of which contain one or more passive-voice tensed verb constructions. That's 11.1%.