Democratic presidential frontrunner Hillary Clinton is portraying herself as the most effective potential guardian of President Barack Obama's legacy.
Her rival Vermont Senator Bernie Sanders, on the other hand, sought to pitch himself as the true personification of change -- at a CNN Democratic town hall in Des Moines, Iowa, on Monday.
Sanders argued that though Clinton has wide experience, she was wrong on key issues such as Iraq, trade, the Keystone Pipeline and Wall Street regulation.
Saying she was "really touched" by Obama's praise for her in a recent interview, Clinton pushed back against questions that asked why some younger voters were less enthusiastic about her candidacy than that of Sanders.
And pressed on whether she was late in addressing income inequality, she said she has spent decades combating inequality of all kinds.
"There are very different visions, different values, different forces at work, and you have to have somebody who is a proven fighter -- somebody who has taken them on and won, and kept going, and will do that as president," she said.
Sanders said: "We need a political revolution. We are touching a nerve with the American people who understand that establishment politics is just not good enough."
Sanders also dismissed Clinton's political record, seeking to prove he was closer to the Democratic Party base and just as prepared to be president as Clinton.
The third Democratic candidate, former Maryland governor Martin O'Malley, argued that he represented a generational change in politics that neither Sanders nor Clinton could match.
Latest polling shows Clinton and Sanders locked in a tight contest in Iowa, where both parties hold caucuses, essentially party meetings, on February 1.
In the most recent CNN Poll of Polls, Sanders edges Clinton 46 percent to 44 percent in Iowa, with O'Malley at 4 percent.
Sanders also tops Clinton handily in New Hampshire, which holds the first primary on February 9.
The Iowa contest is particularly important to Clinton, who lost the state in 2008, setting in motion Obama's path to the White House.
Nationally, however, Clinton tops Sanders 52 percent to 38 percent nationally while O'Malley is far behind the two top candidates at just 2 percent, according to a new CNN/ORC Poll.
Meanwhile, Obama, who has tried to stay neutral between Clinton and Sanders, said Monday that his former secretary of state faces both the "privilege and burden" of being the Democratic presidential front-runner.
On the other hand, "Bernie came in with the luxury of being a complete long shot and just letting loose," he said, in an to the interview with Politico.
Obama said he has spoken to both Clinton and Sanders about 2016, albeit in general terms.
"We've had a conversation broadly about the importance of a Democrat winning (with Clinton), and I've had conversation with Bernie, about issues that he's interested in or concerned about," he said.
Obama also criticised Republicans, saying the party has moved farther to the right after John McCain ran against him in 2008.
"And that's where, ultimately, any voter is going to have to pay attention is the degree to which the Republican rhetoric and Republican vision has moved not just to the right but has moved to a place that is unrecognizable."
(Arun Kumar can be contacted at arun.kumar@ians.in)
