Hillary Clinton's loss to Sen. Bernie Sanders (I-Vt.) in Tuesday's Wisconsin Democratic primary hasn't dramatically altered her still-favorable path to the nomination. But it has heightened concerns within the ranks of her campaign of losing a precious political commodity: time.

Sanders' 13-point Wisconsin win ensured that his melee with Clinton will last at least through April, with its delegate-rich contests in New York and Pennsylvania. Absent Sanders blowouts in both of those states, the math for the nomination will remain quite advantageous for Clinton.

But it likely won't be so clearly in Clinton's favor as to allow her campaign to turn attention and resources fully toward the general election. And increasingly, top Democratic operatives worry that the longer it takes for Clinton to make that full pivot, the more the party ends up squandering the tremendous hand it's been dealt.

"Once you get into May, I think you've got to start having your state directors in place. You have got to start traveling to those [battleground] states. You've got to start communicating to voters in those states," said David Plouffe, who was Barack Obama's 2008 campaign manager. "Now, again, [the Clinton campaign] will make the decision. But having been through this, I think the one mistake you can make is start too late.

"You can't wait till June 8 to start the general election," Plouffe added, referring to the day after the last primaries are held. "That would be a feat of epic political malpractice."

You can't wait till June 8 to start the general election. That would be a feat of epic political malpractice. Obama's ’08 Campaign Manager David Plouffe on the need for Hillary Clinton to pivot soon to the general election.

Plouffe, who backs Clinton, has fairly unimpeachable credentials on the subject of general election pivots. While steering Obama's campaign in '08, he recalled feeling anxious that Sen. John McCain (R-Ariz.) would use the months after he secured the nomination to effectively define the race before Democrats had chosen a nominee. Obama and Clinton were still tangled in their own primary. And the then-Illinois senator could ill-afford to look presumptuous, even with his delegate lead. A portion of Clinton supporters were, at the time, proudly disrupting Democratic events, calling the opposition a "cult," and giving themselves the PUMA moniker: Party Unity My Ass. It was wild.

But McCain didn't use his time well. And that, said Plouffe, "was the gift that we were given." Once Obama won in Indiana and North Carolina in early May, the campaign "started traveling to battleground states that had already had their primaries," said Plouffe. "We started to talk a lot more about the matchup between Barack Obama and John McCain." Unless you've been comatose for the last eight years, you know how the rest went.

Clinton now occupies the same position Obama did eight years earlier: a likely nominee, but not quite a presumptive one, and with a good chunk of her own party potentially aggrieved.

Publicly, Clinton's aides are projecting a touch of nonchalance.

"The month of March put us on a clear path towards the nomination, but the contests in New York and Pennsylvania have the potential to be even more decisive if Sanders fails to achieve significant victories there," said Brian Fallon, Clinton's spokesman. "We expect that by the end of April, it will be undeniable that Sanders has run out of scenarios to overtake Hillary Clinton's delegate lead. It will be clear that she is going to the Democratic nominee."

ASSOCIATED PRESS The primary campaign has gone on longer than anticipated. And it's left party operatives worried that they're squandering general election chances.

Behind the poised facade, however, are real worries -- or at least hurried attempts to find the right balance. Clinton's talking points have grown far more specific to the general election in recent days. She has accused Donald Trump of being serially out of touch and has gone after Ted Cruz for being Trump's temperamental clone.

But the attacks have been undertaken with one eye firmly elsewhere.

Sanders' continued strength, and the slim but real chance that he gets a delegate tally allowing him to either win the nomination outright or persuade party insiders -- the so-called superdelegates -- to rethink their support of Clinton, makes him, basically, un-ignorable. So Clinton and her aides have kept at it, attacking Sanders with lines equal parts biting -- "that he would place gun manufacturers' rights and immunity from liability against the parents of the children killed at Sandy Hook is just unimaginable to me," she told MSNBC on Wednesday -- and dismissive -- "Senator Sanders had a good night last night," she said of his Wisconsin win, "but if you look at the numbers, I am still considerably ahead."

The end result has been a weird, almost asymmetrical posture, with Clinton laying into a candidate that she simultaneously implies doesn't have a chance. But it's a tactic that campaign veterans say is unavoidable.

"I think [the primary] really is effectively over, and I think the Clinton campaign has the dual problem of not taking the rest of the primary off and turning to the general," said Joe Trippi, a longtime Democratic strategist who, most famously, spearheaded Howard Dean's presidential campaign in 2004. "Because once everyone thinks it is over, your opponent starts to win."

Trippi isn't speaking theoretically here. There is evidence, perhaps anecdotal, that insurgent campaigns do better when elections seem to just about crystalize. Clinton rolled up a number of wins late in the 2008 primary. And in 1992, California Gov. Jerry Brown, for whom Trippi worked, chased down Bill Clinton as it seemed Clinton was taking a firm grasp of the nomination. The insurrectionist camp doesn't want to give up, Trippi summarized, and the front-runner's backers get complacent.

Clinton's allies aren't uniformly nervous about this trend as the campaign enters what can be described as a transition period. In fact, they believe that part of their mission entails picking up the general election slack as the former secretary of state tries to shore up the primary. They are even leaving open the possibility of accelerating their plans if that primary drags on longer than anticipated.

"We have been preparing for both Trump and Cruz since the fall of 2015 and will increasingly highlight both of their records in the press, online and ultimately on television," said Guy Cecil, who heads the Clinton-backing super PAC Priorities USA. "While we have already reserved our fall television buy, we haven't ruled out going on the air prior to the convention."

While we have already reserved our fall television buy, we haven't ruled out going on the air prior to the convention. Guy Cecil, head of the Clinton-backing super PAC, Priorities USA

But there is a distinction between a super PAC bearing the load and a campaign doing it. A campaign brings with it a more durable footprint: actual campaign staff doing actual campaign work, as opposed to television ad buys that, at this juncture, can have ephemeral effect.

"It is what the campaign does that matters most," said Plouffe. "It is not even close."

One element of the campaign that works in favor of Clinton and Sanders (should he end up winning the nomination) is that while things may remain in flux on the Democratic side, there is sustained chaos in the Republican race. The need to quickly define the opposition is lessened when it's not exactly clear who the opposition will be -- or, when the opposition is doing a counterproductive job defining itself.

That, at least, was the point made by a former Democratic governor who knows a thing or two about how candidates can be defined in a presidential election.

"I am more concerned about our collective ability to take advantage of what is an extraordinary opportunity not only to win the presidency, but to take back the Congress and lots of other offices as well," said Michael Dukakis, who lost his run for president in 1988. "We can't 'pivot' toward an opponent until we know who the Republican nominee is going to be, and that may take awhile.

"I didn't lose because I didn't 'pivot' early enough. I lost because I made a decision not to respond to the Bush attack campaign, and in retrospect that was a pretty dumb decision."