By James Oliphant
LOS ANGELES (Reuters) - Hillary Clinton heads into what could be a defining moment for her efforts to secure the Democratic Party's presidential nomination this week as she rides a boost from her blistering attack on Donald Trump, her likely opponent in the Nov. 8 general election.
Six states - California, Montana, North Dakota, South Dakota, New Jersey and New Mexico - will vote on Tuesday.
The Clinton campaign hopes the party's front-runner could effectively lock up the nomination early on Tuesday evening with a victory in New Jersey, taking the focus off the fractious battle she has been fighting in California against Democratic rival Bernie Sanders. Clinton may declare herself the party's nominee before the polls close there.
In California, the biggest electoral prize, Clinton once held a sizable lead over Sanders, a U.S. senator from Vermont, but polls in recent days show a dead heat between the two candidates.
A loss to Sanders in California would not derail Clinton's path to the nomination, but it could galvanize Sanders and his supporters to carry their insurgency all the way to the party's nominating convention in July. A loss could also reinforce the argument of Trump, the Republican Party's presumptive nominee, that Clinton is a weakened candidate.
Clinton campaigned on Sunday in Oakland, Vallejo and Sacramento, at one point vowing to take on the powerful U.S. gun lobby, according to NBC News. She is expected to spend Monday in the Los Angeles area.
Passion is running high. Last week, the state reported that the tally of registered voters in California was the highest in history at 18 million, with more than 650,000 registering in the last six weeks. Three out of every four new voters was a Democrat.
In a speech in San Diego last week, Clinton attacked real estate developer and reality TV personality Trump on his national security credentials, arguing he lacked the temperament and knowledge to engage with foreign nations.
Clinton, a former secretary of state, said Trump would be dangerous if left in charge of the nation’s nuclear arsenal, arguing he could use them if offended because he has “thin skin.”
The speech was praised by Democrats who said it could bolster Clinton's efforts to show she could effectively take on Trump in the general election. Even some Republicans said the speech hit a major vulnerability for Trump.
Trump, appearing on CNN, responded to Clinton’s attack.
“I don't have thin skin. I have very strong, very thick skin,” Trump said. “I have a strong temperament, and it's a very good temperament, and it's a very in-control temperament, or I wouldn't have built this unbelievable company.”
The latest Reuters/Ipsos tracking poll shows Clinton with an 11-point edge over Trump, 46 percent to 35 percent, a marked change from just 10 days ago, when fewer than four points separated the two.
(Reporting by James Oliphant; Editing by Bill Rigby)