克林顿预计正式宣布竞选总统

Hillary Clinton is expected Sunday to formally announce her intention to run for president in the 2016 election.

The former secretary of state will announce her campaign for the Democratic Party's presidential nomination with an online video posted on social media, sources familiar with her plans told media outlets.  They said she will then make stops in key early voting states, including Iowa and New Hampshire.

It will be Clinton's second presidential bid after her failed effort in 2008, when Barack Obama won the party's nomination on his way to becoming president. Clinton is considered a huge favorite to win the Democrats' nomination this time.

A recent Gallup poll found 48 percent of those surveyed have a favorable   impression of Clinton, her lowest rating since 2008.  Forty-two percent of those polled had an unfavorable rating of her. 

If elected, the former first lady would be the nation's first female president.

On the Republican side, Senators Ted Cruz and Rand Paul have announced their intention to run for their party's nomination, and Senator Marco Rubio is widely expected to join them on Monday.  Others expected to join what analysts say will be a crowded Republican field include former Florida governor Jeb Bush and Wisconsin Governor Scott Walker.