If I'm following what you're saying, you want us to 1) argue against the person recommended by the previous participant, 2) argue against someone already on the list,
and 3) suggest or endorse someone for the next participant to debunk. Right?
1. Okay, starting with your recommendation:
Elvis Presley. Nothing against "the King", but there is a dearth of musicians on their list - in fact, the only ones I spotted were Ray Charles and Madonna.

If we're going to include another musician, I would think there are more than a few somewhat worthier than Elvis. Like maybe George Gershwin or Aaron Copland or Woody Guthrie or Billie Holiday or Cole Porter or James Brown or John Philip Sousa or Tommy Dorsey or Scott Joplin or Judy Garland or Fats Waller or Frank Sinatra or Leonard Cohen or Philip Glass or Charles Ives or Mahalia Jackson or Glenn Miller or Bob Dylan or Louis Armstrong or Irving Berlin.
And, before I'd add Elvis, I'd want to add those who made his career possible: Jimmie Rodgers, Frankie Laine, Chet Atkins, and - especially - Hank Williams.
2. As for dispensing with someone already on the list, I'd have to go with ousting
George Lucas. I mean,
come on - the guy has directed - what? -
THX 1138, American Grafitti, and four of the awful
Star Wars movies? And he gets a place on the list ahead of such American directors as Woody Allen, Robert Altman, Tim Burton, Frank Capra, Charlie Chaplin, Francis Ford Coppola, Clint Eastwood, John Ford, John Frankenheimer, D.W. Griffith, Howard Hawks, John Huston, Buster Keaton, Stanley Kubrick, Ernst Lubitsch, Mike Nichols, Martin Scorsese, Preston Sturges, Orson Welles, and Billy Wilder??? Puh-
lease.3. And as for endorsements or additions, well there are obviously quite a few people that I feel
do belong on their list. But, as this is a political site, I'd have to say that the inclusion of such noted politicians as Jackie Kennedy, Richard Nixon, Hillary Clinton, and Laura Bush are a bit surprising when we don't include people like James Madison, John Jay, Aaron Burr, Andrew Jackson, Salmon P. Chase, Jefferson Davis, Ulysses S. Grant, Oliver Wendell Holmes, Woodrow Wilson, William Howard Taft, J. Edgar Hoover, Adlai Stevenson, and Earl Warren.

Maybe they're not as "great" as Barbara Bush, but I'd say they were somewhat more influential.
For my addition, I'm going to go with
Eugene V. Debs, labor leader, civil rights and anti-war activist, and five-time candidate for the US Presidency on the Socialist Party ticket - the last time garnering a million votes
while in federal prison. He had been arrested under the Espionage Act of 1917 for opposing World War I and was sentenced to ten years and permanent disenfranchisement:
QUOTE
Your Honor, years ago I recognized my kinship with all living beings, and I made up my mind that I was not one bit better than the meanest on earth. I said then, and I say now, that while there is a lower class, I am in it, and while there is a criminal element, I am of it, and while there is a soul in prison, I am not free.
His sentence was commuted by Warren G. Harding and his citizenship was posthumously restored in 1976.