The ad shows a clip of Santorum struggling to name Marco Rubio's accomplishments.
Trump's stinging loss in the Iowa caucuses robbed him of his sense of momentum.
"Senator Rubio did not tell the truth last night on that stage," Christie said.
Christie-2016.com shows Christie with Obama and says, "You can do better, America."
"I take heat for what I say all the time and sometimes it's deserved," says Christie.
He said New Jersey was in good shape after the storm.
Iowa's caucuses are one week from Monday.
Sanders, Trump, Clinton, Bush and Christie are among this week's guests.
"I want to make sure the people of my state feel safe and secure," he said.
Christie said Granite State voters are turned off by negative attack ads.
New Jersey Gov. Chris Christie tore into first lady Michelle Obama's healthy food initiative Monday...
OPINION: It is simply untrue to suggest President Obama is equally culpable.
Christie has been increasing his attacks on Rubio since the Iowa caucuses.
Christie accused Rubio of evading questions.
"None of the rest of us do that," Christie says of phoning in for interviews.
“I think it makes people call into question his judgment,” Christie said.
The New Jersey governor bashed Common Core and the agency under President Obama.
"I don't know what critics you're talking about," he told Huffington Post editor Sam Stein.
“Fourteen people died across the country," Christie said.
Trump and Cruz are skeptical of the science behind climate change.
It is the second poll to find Christie losing ground in the Feb. 9 primary.
Trump leads the race with 36 percent support nationally.
So far, only a few Republican presidential candidates back Obama's agreement.
No Republican candidate was safe during last night’s parody.