Hillary Clinton started the Democratic primary season last year with polls showing her as the strongest non-incumbent candidate for president in modern American history. Next week, she is expected to clinch the Democratic nomination by limping through the final round of primaries with just enough delegates.

This is certainly not the trajectory any candidate would like, but it is unclear whether Clinton’s bruising primary season portends anything about her chances in the general election.

America is still a divided nation of Republican states, Democratic states, and swing states. And while Americans may not like her as much as they did when she was secretary of state, polls also show they dislike her Republican opponent even more.

“A lot of this is the expectations game,’’ said Bruce Cain, a Stanford University political science professor. “No one expected Donald Trump to be the nominee, so he looks more triumphant, where everyone expected Clinton to dominate and that didn’t happen.’’

In the 15 months since Clinton entered the contest, her personal favorability numbers have nosedived. Polls show this is largely a result of negative news stories about how she handled her e-mail while serving as secretary of state, resurfacing doubts about whether voters could trust her. Clinton shirked federal policy by using her private e-mail while in that role, and federal investigators continue to look into the matter.

In March 2015, a month before Clinton entered the race and just before revelations about her e-mail usage were public, Gallup released a poll that, according to a press release, showed Clinton in “a better starting position regarding her image than other competitors would have in the 2016 US presidential election.’’ That poll showed Clinton was viewed favorably by 50 percent of voters nationwide, while 39 percent reported the opposite.

But the most recent CBS News/New York Times poll shows those numbers have flipped. In late May, 52 percent of survey respondents said they do not have a favorable opinion of Clinton, while 31 percent did.

In some ways, Clinton’s decline in the polls was inevitable — even without the e-mail controversy. It’s part of the process of a contested primary season, according to Mo Elleithee, who served as Clinton’s traveling press secretary in 2008.

“This was supposed to be a coronation for Al Gore in 2000, and then John Kerry in 2004, and even Clinton in 2008, until they all got a primary challenger,’’ said Elleithee, who now leads the Georgetown Institute of Politics and Public Service. “Democratic primary voters want a primary, and they want to see candidates earn it.’’

“Is Hillary in a worse off position than when she started? OK,’’ Elleithee continued. “But in nearly every metric she is in a better position than Barack Obama was after the primary in 2008, and that is what matters now.’’

Cain, the Stanford professor, agrees.

“What we are seeing play out in this Democratic primary campaign is what many of us have said has always been there: the traditional divide among Democrats,’’ Cain said. “But this changes in the general election when Clinton doesn’t face a likeable ideological opponent, but someone like Trump who is just as well-liked as she is.’’

But one of Clinton’s challenges will be to heal the divide among Democrats. The latest ABC News/Washington Post poll found that 20 percent of Bernie Sanders’ supporters say they will not vote for Clinton. For context, the same poll in June 2008 showed 40 percent of Clinton supporters would not support Obama in the general election.

Republicans, however, do point to Democratic primary season as proof that Trump may have a leg up on Clinton.

Trump’s former national political director, Rick Wiley, told Bloomberg he believes Trump could win because of the enthusiasm gap in particular swing states. While Trump was drawing passion and big audiences, Clinton was getting smaller crowds, he said. Wiley pointed to a Roanoke College poll that showed Republicans in Virginia, a politically competitive state, were more excited than local Democrats about the election by 11 percentage points.

Democrats like Elleithee said the party will eventually get behind Clinton. But at least one Republican on the ground in the presidential battleground state of Ohio believes the enthusiasm gap is something to watch.

“In a lot of ways, the general election here has the same dynamics like all others,’’ said Alex M. Triantafilou, chairman of the Republican Party in Ohio’s Hamilton County, one of the most watched regions in the country on election night. “Where it feels different after the primary season, is that there seems to be more passion on our side. Admittedly not all of the passion for our candidate is good passion, either.’’

James Pindell can be reached at james.pindell@globe.com. Follow him on Twitter @jamespindell or subscribe to his daily e-mail update on the 2016 campaign at www.bostonglobe.com/groundgame.