Times video: Is Hillary Rodham Clinton’s book tour a warm-up for 2016?

Presidential campaign seasons have many starting points: when a candidate hints at a run, when a candidate announces an exploratory committee, when a candidate announces that an announcement is on the way, and when the announcement finally comes (which is always an anticlimax).

But there’s another, less official time line. And that one is already well underway for 2016. Some may peg the start of it in January, when New Jersey Gov. Chris Christie’s bridge closing scandal blossomed, putting his aspirations to higher office in jeopardy. A nation of politics junkies, including other potential contenders and donors, pricked up their ears, sort of like animals do when they hear the thump of a tree falling in a forest.

While potential Republican White House contenders have roamed around the country, more or less quietly building their cases, Democrats have been sitting on their hands, waiting for former secretary of State Hillary Rodham Clinton to make a move.

And now she has.

Oh, sure, her current publicity blitz is ostensibly for her new memoir, “Hard Choices.” But everyone knows her nonstop interviews and book signings are a warm-up for a possible presidential run. Testing the waters this way is smart. She gets millions of dollars of free publicity, sells a ton of books about her four years as secretary of State, gives her side of the tragedy in Benghazi, and in the process gets to see where she’s weak and needs help with her message.

Already, she’s demonstrated that being off the political battlefield for four years has dulled her political instincts.

Anyone on her game would never have complained about being “dead broke” at the end of her husband’s eight-year presidency, what with her $8-million advance for her first memoir, “Living History,” and Bill Clinton’s limitless financial prospects.

By Thursday, however, Clinton seemed in fine political form as she fended off a series of pointed questions by Terry Gross of the radio show “Fresh Air,” who pressed her repeatedly about the evolution of her stance on gay marriage. Gross seemed to want Clinton to admit that she’d been for gay marriage all along, even in the 1990s when her husband signed the Defense of Marriage Act, and only embraced it when gay marriage became politically palatable. Clinton repeatedly rejected that notion, and said that she, just like the rest of the country, had evolved.

“I did not grow up even imagining gay marriage,” said Clinton, “and I don’t believe you did either.”

In this week’s Times video, my colleague Ann Simmons and I discuss the rollout of Clinton’s memoir and how her behavior on the book tour may foreshadow a political campaign.