By John Whitesides
DES MOINES, Iowa (Reuters) - When Democratic rivals Hillary Clinton and Bernie Sanders take the stage in a presidential debate on Saturday, Sanders is likely to be more aggressive than in their first debate as he highlights their differences on issues like reducing income inequality.
When they faced off last month, Sanders was restrained in challenging Clinton and got a grateful handshake from her when he said voters were "sick and tired" of the controversy over her use of private email as secretary of state.
This encounter will be different.
"He's not necessarily looking for a fight, but he does have some differences with her on issues and he intends to talk about those," said Tad Devine, a senior adviser to Sanders.
Sanders has turned up the heat on Clinton on the campaign trail, questioning her sincerity and trustworthiness after she reversed course to join ranks with him and other opponents of the Asian trade pact and Keystone XL pipeline.
But with Clinton well ahead in polls, the Vermont senator is preparing to engage her on other policy differences as well. Sanders, a self-described democratic socialist, told the Boston Globe last week that he disagrees with the more moderate Clinton on "virtually everything."
Devine said he "wouldn't be surprised" if Saturday's debate was more testy.
"He really wants to have a debate on the issues," Devine said, citing campaign finance, college affordability and climate change as other topics where he could draw distinctions with Clinton.
"But if there is conflict, if anybody questions him or goes after him on an issue, he'll be prepared to engage," he said.
The debate in Des Moines, Iowa, will be televised by CBS News and begins at 9 p.m. EST. Clinton, Sanders and Martin O'Malley, the former Maryland governor, will participate.
Former Rhode Island Governor Lincoln Chafee and former Virginia Senator Jim Webb dropped out after the first debate.
The encounter follows a good month for Clinton. A strong performance in the first debate and a forceful 11-hour appearance before a congressional panel probing the Benghazi attack calmed Democratic fears after a summer of controversy over her emails.
Clinton also was buoyed by Vice President Joe Biden's decision not to launch a White House bid against her.
Polls show Clinton now has a commanding double-digit lead over Sanders nationally and in Iowa, which holds the first nominating contest on Feb. 1. O'Malley trails well behind, registering in single digits.
(Editing by Christian Plumb)