On Tuesday's Good Morning America, reporter Jake Tapper attacked the "bizarre," "non-reality-based" conspiracy theory about President Obama's birth certificate. Yet, the ABC program has not done a similar expose on the belief that the government was involved with, or knew of, the 9/11 terror plot.

Speaking of the false idea that the President was born somewhere other than Honolulu, Tapper described it as the "bizarre conspiracy theory that is as seemingly persistent as it is erroneous. It is the lie that will not die." In contrast, GMA lacked such outrage for truthers and repeatedly promoted Rosie O'Donnell, ignoring her own weird and baseless agenda. 

(Although host George Stephanopoulos did grill conspiracy theorist Jessie Ventura on April 4, 2011 about his truther ideas, the show hasn't devoted a full segment to the topic.)

When O'Donnell, who believes the Twin Towers were taken down by a controlled demolition, appeared on the April 08, 2008 GMA, then-host Diane Sawyer praised the comedienne's "singular" vision. She never mentioned trutherism.

Stopping by the morning show on January 26, 2010, O'Donnell lectured Stephanopoulos to not grill her. He didn't.

On May 29, 2007, the morning show hosts investigated why O'Donnell "really" left The View (her daytime ABC program). They skipped 9/11.

A segment on April 03, 2007 also left out the liberal comic's bizarre theories.

Then-co host Charlie Gibson on May 16, 2002, seemed to flirt with the idea of trutherism when he introduced a story on President Bush:

"This is interesting news that we get now, and it may put the President under a lot of heat today as the public learns that he knew, through his daily CIA intelligence briefings, that bin Laden had potential terror attack plans under way....It also calls into question what happened when Andy Card, Andrew Card, the White House chief of staff, that morning went and whispered in the President's ear, as the President was talking to a group of school students in Florida. Was the President really surprised?"

– Charles Gibson’s introduction and question to White House correspondent Terry Moran on ABC’s Good Morning America, May 16,2002.

A transcript of the April 12 segment, which aired at 7:11am EDT, follows:

ABC GRAPHIC: Obama's Sister Defends President: Speaks Out on "Birther" Controversy"

STEPHANOPOULOS: Even though he may only be toying with the idea of a White House run, Donald Trump is drawing the kind of fire that comes with a full fledged campaign. On Sunday, President Obama's top political advisor called him out for questioning the President's citizenship. And now, Obama's sister, Maya Soetoro-NG, has joined the fray too. Jake Tapper has been following it all from the White House. And, Jake, she's been keeping a fairly low profile. Why take this on now?

JAKE TAPPER: Well, she's on a book tour promoting her children's book when she was asked about this bizarre conspiracy theory that is as seemingly persistent as it is erroneous. It is the lie that will not die, the notion that President Obama was not born in Honolulu in 1961 as stated in his certificate of live birth and backed by the state of Hawaii, contemporaneous birth announcements submitted by the State Department of Health and the President's half sister in an interview that will air tonight on CNN's Piers Morgan.

MAYA SOETORO-NG: I think it's unfortunate. He was born in Hawaii. There is a tremendous amount of proof that has already been accepted. I think that it is time for people to put that to bed, to put it to rest completely.

TAPPER: This time, the birther nonsense was resurrected by real estate developer and would-be Republican presidential Donald Trump, who put forward a number of false accusations, such as the claim that the released certificate of birth does not have a serial number. [Buzzer sound.] Or a signature. [Buzzer sound.] And on and on. Trump is likely doing this to appeal to Republican primary voters. A Fox News poll shows from this month shows that 37 percent of falsely believing the President was not born in the U.S., compared to 47 percent who do. Some Republican officials fear this line of nonsense will undermine the Republican presidential field.

KARL ROVE: This is a mistake. It will marginalize him.

TAPPER: Because while it has an appeal to some in the Republican base, independent voters worried about jobs and the economy, think the birther conspiracy theories are ludicrous.

ROVE: The vast majority of Republicans and the vast majority of Americans accept that he's a U.S. citizen and capable of being President.        

PIERS MORGAN: What do you think about Donald Trump banging on about this every day at the moment?

SOETORO-NG: Well, I think it's a shame and I think my brother should definitely be President for a second term.

TAPPER: And, Robin, the concern about Republican officials is that Republican presidential candidates will be forced to respond to this nonsense and they will either pander to the non-reality based, or risk alienating them. And that's a choice no politician ever wants to face. Robin?

— Scott Whitlock is the senior news analyst for the Media Research Center. Click here to follow him on Twitter.