No.1 target for GOP debate: Trump

Republican presidential candidate Donald Trump speaks during a campaign event aboard the retired ship USS Iowa in Los Angeles on Tuesday, Sept. 15, 2015.

Kevork Djansezian/AP

The Republican presidential candidates meet for their second debate Wednesday night. Once again, Donald Trump will be front and center.

What to expect from second GOP debate

Eleven candidates will appear in primetime at the Ronald Reagan Presidential Library in Simi Valley, California.

The last time Republicans met for a debate, Trump was the novelty front-runner. The novelty has now worn off, and Trump, still the leader of the pack, is now a target -- of Republicans, Democrats and immigration protesters.

Trump stood on the USS Iowa Tuesday and declared his competition unfit for office.

"They are very nice people. But they are never going to do anything with these countries -- they are never going to be able to do it," Trump said. "It's an instinct, something that's special, they don't have it, believe me, they don't have it."

Trump also received an endorsement from the conservative group, Veterans for a Strong America, which he said he didn't expect or ask for.

On-shore protesters heckled Trump, denouncing his positions on immigration.

While Trump's lead remains, retired neurosurgeon and fellow political novice Dr. Ben Carson has risen to second place.

Now a key conservative group is taking aim at Trump on TV for the first time. Club for Growth released a new ad Tuesday that compares Trump to leading national Democrats.

"Trump wants us to think he's Mr. Tell-it-like-it-is. But he has a record... and it's very liberal. He's really just playing us for chumps," the ad said.

Vice President Joe Biden, edging toward a presidential run of his own, attacked Trump Tuesday night at an event honoring Hispanic heritage month, blasting the Republican candidate's hardline immigration plans.

Biden blasts Donald Trump's immigration rhetoric

"One guy absolutely denigrating an entire group of people, appealing to the baser side of human nature, working on this notion of xenophobia in a way that hasn't occurred in a long time... The Trump and the stuff you are hearing on the other team... it's about a sick message," Biden said.

A sympathetic crowd cheered for Biden afterward, chanting, "Run, Joe, run!"

For Republicans, the other big story has been the rise of Carson and the fall of Jeb Bush and Scott Walker. Carson told CBS News that ‎he and Trump have caught fire because GOP voters are tired of being "hoodwinked" by establishment Republicans.