The controversy is not about how she used the account to communicate. It is about how she seized control of the account and its emails, which belonged on a government server.
Why it matters: A homebrew server gave Clinton full control of government records. She didn't explain why she wanted control badly enough to defy regulations and the president. Theoretically, she could delete or withhold public documents without the public ever knowing.
QUESTION: Does she consider emails about her family foundation to be personal?
Forced by House Republicans to acknowledge the existence of a rogue server, Clinton deleted more than 30,000 "personal" emails before giving the State Department a cache of emails she deemed to be work-related. How does she define personal? Emails about her mother's funeral, for example, and her daughter's wedding. No reasonable person would expect public disclosure of those kinds of emails.
Why it matters: Clinton could convince herself that emails about the Bill, Hillary & Chelsea Clinton Foundation are not government-related. After all, it's a private charity. But it's also a well-funded conflict of interest—the subject of multiple investigative stories exploring connections between donations and favors done for donors. You don't have to be a Clinton critic to wonder whether the deleted emails involve pay-to-play. Democratic loyalists wonder, too.
Beware of Clinton spin. Her team is already trying to cast this as a brave fight to keep her private emails from public view. That's a straw man. What she is doing is waging a fight to keep control of emails that were supposed to be in the government's possession.
QUESTION: Do Democratic leaders honestly believe Clinton is their best candidate?
Why it matters: When she strode into the United Nations news conference to belatedly and dismissively address the email flap, Clinton was the presumptive Democratic nominee. She left the room still atop the heap, though no less embattled and discredited. "It was all so very yesterday," New York Times columnist Frank Bruni writes. "And elections are about tomorrow. Yes, that's a cliché, but it's also the unassailable truth." Less elegantly, I wrote that Clinton's handling of the situation shows her to be "a pay phone candidate in an iPhone world."
QUESTION: Does she really want to run for president? Does she want to endure a process subjecting herself to scrutiny, skepticism, and post-Internet transparency?
Why it matters: The world has dramatically shifted since a Clinton last sat in the Oval Office. Deflecting, attacking, spinning, lying, and other tricks of the 1990s are far less effective in an era of democratized media, when Clinton's harshest critics and fair-minded skeptics will pierce Clinton's defenses.
This is a messy new world for a person who demands control and can't stand her motives being questioned. Why run if the process is such a pain? Why seek a job that now requires something she abhors: transparency.
Why it matters: Her rule-breaking and obfuscation force anybody who is not paid by Clinton or blindly loyal to ponder an uncomfortable choice. Clinton either has no idea how much damage she's doing to her image and her party (which doesn't speak well of her crisis-management skills) or there is something untoward in those emails.
It would be nice if we could all assume the former: She's just a lousy candidate, not a liar or a crook. But the vast majority of Americans have no faith in politicians, politics, or government. Most know the Clintons' history of stonewalling. And to those people, her answer to legitimate questions about government email and the Clinton Foundation is, "Trust me."