Cdesign proponentsists frequently claim that intelligent design is not creationism. For example, David Klinghoffer says:

…intelligent design is not the same thing as creationism.

Casey Luskin:

…the reason “intelligent design” terminology came into widespread use was because ID proponents knew their project was distinct from creationism in important ways.

Michael Flannery:

Of course, ID is not creationism.

Stephen C. Meyer:

Intelligent Design is not Creationism.

Jonathan M.:

…whereas intelligent design could be defined as the study of patterns in nature that bear the hallmarks of intelligent causality, Creationism is an attempt to interpret the world in view of a religious text such as Genesis 1.

Granville Sewell:

…as far as I knew, I was the only ID proponent in the world in 1985. I had never heard of anyone else who doubted unguided evolution yet didn’t believe in what would today be called “creationism.”

Under a narrow definition of creationism (such as Jonathan M.’s above), this is true. But creationism is a bigger tent than that. The definition in Biology and Creation, an early version of the book that played a central role in Kitzmiller vs. Dover, Of Pandas and People, is

Creation means that the various forms of life began abruptly through the agency of an intelligent creator with their distinctive features already intact. Fish with fins and scales, birds with feathers, beaks, and wings, etc.

So according to the creationists themselves, creationism is a rejection of common descent. And cdesign proponentsists believe in common descent, right? According to David Klinghoffer,

Dear Professor Barash, No One — No One! — Denies the Interconnectedness of All Life

Dear Mr. Klinghoffer, you should read more Evolution News and Views. Never mind, I’ve taken the hit for you. It’s true that most of the Discovery Institute fellows don’t reject common descent. Michael Behe accepts common descent [all of the emphasis in the following quotes is added by me]:

I am not a creationist and have no reason to doubt common descent.

as does Michael Egnor:

Universal common ancestry is a reasonable inference from the evidence, and life evolved over several billion years.

Denyse O’Leary hedges a bit:

Look, I do not have a problem with common descent, until its advocates get up on their hind legs and start arguing for it.

but doesn’t outright reject common descent:

I accept NASA’s estimate of our Earth’s age (4.5 billion years) and consider common ancestry a reasonable idea.

But not everyone is on board. Casey Luskin has his doubts:

Perhaps the inability to construct robust phylogenetic trees using molecular data stems from the fact that common descent is simply wrong.

And more recently:

Convergent Evolution Challenges Darwinism and Destroys the Logic Behind Common Ancestry.

Jonathan M. has a whole series of posts on common descent, including this one:

Many of us Darwin critics, therefore, also happen to be skeptical of common ancestry.

Stephen C. Meyer asserts that

The transitional life forms that ostensibly occupy the nodes on Darwin’s branching tree of life are unobservable…Transitional life forms are theoretical postulations that make possible evolutionary accounts of present biological data.

Jonathon Wells refers to

…speculations about common ancestry and the transmutation of species that look increasingly implausible with each new piece of evidence.

John G. West also has his doubts:

…some of the reasoning used to support common ancestry seems circular and the evidence for universal common ancestry seems lacking.

So “No One — No One! — Denies the Interconnectedness of All Life” is a bit of an exaggeration  a lot of an exaggeration  a lie. A substantial subset of Discovery Institute fellows do reject common descent, and there’s no way David Klinghoffer doesn’t know it. A large portion of the posts on both Evolution News and Views and Uncommon Descent argue against common descent. Does that make the authors creationists? Not by itself. It is, in principle, possible that universal common ancestry could be false, in other words that there could have been more than one origin of life. There’s no evidence that it’s true, but it’s not an unscientific idea. If some deep sea dredge, like the one that collected Lokiarcheota, pulls up an organism with a genetic code completely unlike ours, we would have to consider the possibility.

But denying that the life we do know about shares a common ancestor…yeah, that’s pretty much creationism. Even the most hardcore Young Earth creationists (these days) mostly accept common descent within ‘kinds’ or ‘baramins‘. For example, the Institute for Creation Research is all about the baramins: see for example here, here, and here. Something like this is necessary to explain how we can have millions of species and fit them all on a 300 cubit ark.

There is a near continuum between biblical literalism and purely naturalistic evolution, including Old Earth creationism, acceptance of limited or microevolution, and evolution with varying degrees of intervention by a designer. Cdesign proponentsists lie at various points on that spectrum, but some of them are closer to the Young Earth creationism end than the ones closer to the naturalistic evolution end of the spectrum would like you to believe. If you reject common ancestry — as Casey Luskin, Jonathan M., Jonathon Wells, John G. West, and Stephen C. Meyer do — then you are closer to the creationist end of the spectrum than some people who self-identify as creationists. In that case, I think it’s fair to call you a creationist.

EDIT (2019-07-04): fixed some links in response to rjdownard’s comment.