Tuesday marks the anniversary of Hillary Clinton getting into the 2016 presidential race. It has been a year of surprises.

Clinton launched her campaign with a YouTube video in which she tells voters she's "getting ready to do something." She led a Democratic field by over 50 points. Jeb Bush was expected to be her main opponent on the Republican side. Less than 5 percent of the country had ever heard of Bernie Sanders.

Many spoke of Clinton's campaign as being "inevitable" in the beginning, and while she remains the strong front-runner, it hasn't always been easy.

It was expected that Clinton would be the likely Democratic nominee. But here are a few unexpected things that have defined her campaign.

The rise of Bernie Sanders. Many progressives hoped Massachusetts Sen. Elizabeth Warren would challenge Clinton in the primaries. She was the subject of draft attempts by MoveOn.org.

While they wanted Warren, they got Sanders instead. The aging socialist senator from Vermont declared for president while his supporters ate Ben and Jerry's ice cream and danced to folk music.

Sanders' talk of a rigged economy that benefits only the wealthy caught on. He quickly surpassed Martin O'Malley, Jim Webb and Lincoln Chafee. They are gone from the race. Only Sanders remains.

Sanders beat Clinton in New Hampshire, where she had won in 2008. He is currently on an eight-state winning streak against Clinton. And he has helped move Clinton to the left.

Today, Clinton leads Sanders 1,756-1,068 and is on track to win the necessary 2,383 delegates before the Democratic convention in Philadelphia this summer.

No Joe Biden. While Sanders was unexpectedly strong, the Clinton campaign feared Vice President Joe Biden would get into the race.

All through the summer, word went out that Biden's decision was just around the corner. A super PAC was set up to draft Biden. There were conflicting reports about whether the death of his son Beau made it more or less likely he would run.

Fortunately for Clinton, Biden took a pass on 2016.

Email scandal and a matter of trust. Clinton'said use of a private email server in her home while secretary of state raised questions about whether she was shielding herself from transparency requirements and putting classified information at risk.

Clinton's server became the subject of an FBI investigation, and the State Department released batches of her emails to the public under court order.

Clinton's image also took a hit when it was reported she earned hundreds of thousands per speech to Goldman Sachs at a time when Democrats are critical of Wall Street.

A year later, 57 percent of voters don't believe that Clinton is "honest and trustworthy," according to the latest Washington Post/ABC News poll. Exit polls suggest she usually loses Democrats looking for a trustworthy candidate in the primaries.

A new GOP challenger. Clinton was preparing for a general election campaign against either Jeb Bush or Scott Walker. Instead, the Republican front-runner is former donor Donald Trump. The Clinton's attended Trump's wedding to his current wife.

Clinton has adopted a strategy of running against Trump's rhetoric to heighten hefty appeal to young voters and minorities. She describes his words as divisive, hateful and even racist, as she portrays Trump as representative of the whole Republican Party.

With six and a half months left until the general election, general election matchup polls show Clinton leading Trump 49.6-39.0 percent, according to the RealClearPolitics average of national polls.