Well, that depends on exactly how you choose to define bad.

Consider Mein Kampf, his seminal book with respect to the concepts of racial purity and the inherent superiority of one ethnicity above that of another ethnicity of humans.

It is clear from reading this book that Hitler was considerably hateful and racist in and by any measure you can reasonably choose.

Secondly , he was singularly ambitious in so far as he felt it was (more or less) his calling to lead the German/ Austrian/ Prussian people.

Thirdly, he had a particular area of focus of his hatred - generally "undesirables" and specifically "Jews" and other non-Aryan "races/ethnicities".

Common misconceptions about various social concepts, that were popular in the 1860-1940's, particularly the idea that the concepts of the scientific principle of evolution could be considered to extend into social systems, as a variant of "Social Darwinism".

The rise of national socialism in Germany/Austria is a direct result of a hard-line conservative reaction to the possible influence of communists or liberal democrats, and the huge influence of propaganda, to obtain and maintain power.

As a society, we in the west, do a serious dis-service to ourselves in labeling , Osama bin Ladin, Adolph Hitler , Mao Zedong , Al Gore or George Bush as "evil", primarily this is an infantile response which closes off further discussion or analysis and tends to remove "that person" or "persons" from further rational examination.

The movie "Downfall" gives an excellent characterization of the character of Hitler towards the end fo the war.

It is important to understand that not only was Chancellor Hitler human and reasonably intelligent, but he was personally quite charming as many contemporaries have attested to.

Prime Minister Winston Churchill himself, is quoted as having said that he was personally thankful that he never met Hitler since many of the politicians whom he admired - whom HAD met Hitler could not bring themselves to see Chancellor Hitler for the monster he was.

They universally, had profound difficulty in mentally getting their heads around the fact that the Chancellor was by most all accounts extremely charming and charismatic personally and also the fact of the aggressive international actions and later the monstrous crimes against humanity of the German administration and state apparatus.

Furthermore, we did not - in human history - until that point ever have a circumstance where a modern , democratic state had instituted a purposeful extermination program on the scale that the German Reich did.

Most other states did perform relocations or smaller-scale exterminations (Such as the military actions at Wounded Knee, or (at that time) the Armenian Christian "relocation".

The closest equivalent to the German "Racial Purity" program, was the social hygiene programs setup in the Southeastern US, whereby mentally retarded citizens were routinely chemically sterilized (from the 1910's thru the 1940's).

The US also - unfortunately has the closest historical analouge to a death camp, - that of Andersonville, during the Civil War. Andersonville was not so much an intentional death camp so much as a victim of circumstance and was certainly NOT unique to the Confederacy or the Union.

(http://www.censusdiggins.com/cw_pow_photo.html)

So what Churchill and Roosevelt had to contend with was the "perfect storm" of morally reprehensible policies and actions, all rolled up into a single administration.

Coupled with the historical German efficiency, this means things got REALLY bad really efficiently.

So while we (from above) KNOW that Hitler not only was charming and charismatic in person but also an amazingly compelling orator we also know from official correspondence that Hitler did in - horrible truth - have a squeamish/sensitive side.

Iris Chang's excellent book "The Rape of Nanking" describes the Japanese occuption of the Chinese city of Nanking, (lasting a little less than 7 weeks) during which time over 300,000 civilians were systematically raped and or executed.

One of the ironic (if ever the word had meaning) hero's at Nanking, was the German Ambassador , whom personally knew and appealed to Chancellor Hitler , writing impassioned letters back to Berlin, detailing the atrocities and "to please send planes and ships as possible" to help evacuate the Chinese out of the city. After several days of continuous communiques' to Hitler in Berlin. After several days, and after sending some small help, Hitler's staff wrote back asking not to send any more details as they were "emotionally disturbing the Chancellor".

So here we are, deprived of simply dismissing Hitler as evil and moving along, worse yet, we find the Chancellor had a soft-side, he was kind to his secretaries, thoughtful in correspondence, and disturbed by hearing reports about atrocities, very much along the lines of those being committed within his own concentration camps.

However, this is NOT an attempt to rehabilitate Chancellor Hitler as "not such a bad guy" after all. He was - in as much as our species has produced - a monster , but NOT a monster removed from us, but a monster very much a part of us.

Here then when we say "Hitler was evil" we purposefully blind ourselves to the more important questions, of how exactly that circumstance occurred, and the important questions which get to how do we PREVENT such atrocious policies and actions from occurring in the future.

And on this matter, the short answer is we haven't learned much at all.

Consider the militancy and hard-line rhetoric used by the very survivors (and their children) of Hitler's concentration camps.

We consider nothing less than today's headlines regarding the ethnic cleansing of central Sudan by Islamic militants , or the radicalized Taliban militia instituting fatwas that all non-Muslims must wear arm-bands identifying themselves as Hindu, Jew, Christian etc.

Consider the world reaction to the largely successful genocides of the Tutsi minority of Rwanda. (over 70% "effective" at the end of the day) in the Spring of 1994.

The open wound that is the Israeli/Palestinian conflict, where the Jewish people and Israelis in particular have conducted a "defensive" ethnic cleansing.

Above all others as much as they can be sympathized with for having endued such atrocities as those suffered under Chancellor Hitler, one of history's great ironies, is to see the same arguments of ethnic / religious destiny or superiority used by the German Regime, used by some Jewish Israeli political and military leaders today , the very descendants of the victims of that same argument targeting another group of people in sometimes exactly the same ways.

Furthermore, if we consider the course of actual dead souls the best proxy, then Hitler ranks a very strong #3, on the list of most destructive personages of the 20th century.

#1. Chairman Mao Tse Tung/Zedong, through attrition, or systematic abuse something between 14-25 million Chinese, and some suggest as many as 40 million Chinese, may have been killed in / through various programs from the early 1950's until the early 1970's.

#2. General Secretary Josef Stalin, has certainly been nearly as deliberate as Chancellor Hitler in his extermination of non-desirables (particularly Jews, Cossacks and Georgians as well as political deviants of any stripe), his nearly 30 year iron grip on the Soviet state apparatus means that through attrition, famine and suppression, no less than 10 and more likely approaching 20 million "surplus" Soviet citizens died as a result of the General Secretary's direction and policies.

Suffice it to say, the death of 8-12 million at the very least puts Hitler in the big leagues as far as numbers dead.

As far as Hitler's personal awareness - it's quite clear based on the testimony of various personal associates of the Chancellor that he was well aware of the extermination camps.

It's then fair to say that what we despise and should rightly give us concern then is not the "evil" nature some ascribe, but his complete socio-pathology, his ability to be selectively rational, sensitive, and genocidal at the same time.

Similarly we today see - or choose not to see - perhaps, that our President, has in fact set up similar conditions, where there are "secret camps" , for "undesirables", and that we the people, should simply trust that our leadership is not doing bad things behind closed doors.

Unfortunately, we know, from various reliable sources that in fact we do torture - sometimes fatally , the detainees in our custody.

The uncomfortable truth about Chancellor Hitler today, is that most Americans are perfectly comfortable with nearly ALL of the same circumstances that existed in greater Germany, and we just console ourselves (and not much of anyone else), in suggesting that we're different in kind, when in fact we are only different in degree or quantity.