Have Lincoln and Kennedy Set the Standard for Presidential Assassinations?

I'm sure all of you like myself have heard the concern of many of the possibility of Barack Obama getting assassinated as president. I often think about the psychology of this concern and why people point the finger at Obama getting shot that no one questioned when Kerry or Gore ran. Or when Clinton and Bush were President. The first obvious explanation is his skin color. Many are afraid that white supremacists will try to assassinate him because he is black.
Should this be a concern? Yes. Is it a likely scenario? I don't think so. When I think about a white supremacy group going up against the Secret Service and the FBI who will protect the President it doesn't seem likely to me that they will be able to pull off an assassination. To shoot a president would be no easy task, especially in the United States. It would take a high level of sophistication in the strategic planning and execution of the plan. Maybe you do, but I don't give white supremacy groups that much credit. I don't find them to be that bright. Mostly a bunch of uneducated thugs.
But Obama is a trans formative figure with great communication skills and an angle for governing that comes from outside the box. It's starting to smell like Lincoln and Kennedy. Lincoln was the first Republican ever elected to the presidency, Kennedy the first Irish Catholic, and Obama is the first African-American President. All three of these men have been very glamorous political figures with an eloquence in the way they speak that can woo the masses like no other can. The country has also chose to invest all of its hopes for the future in the persona's of these three men. But history taught us with the first two that the dream will always end abruptly with a gunshot forever changing history and stunting the progress that has been made.
More importantly though, all three of these men have/had great agenda's for change in America that can be extremely threatening to the power elite who have a vested interest in opposition of these agenda's. Did the Civil War and ending slavery play a role in why Lincoln was killed? I believe so. Was Kennedy's goal to end the Cold War with Russia and avoid combat operations in Vietnam involved in deciding to kill him? I believe so. Will Obama's agenda and attempts to make America a little better for everyone (like Lincoln and Kennedy) and not just the privileged few make him a candidate for assassination? I don't know and this is the level I can see an assassination attempt happening on.
However, there is a difference. Andrew Johnson was a different kind of politician, a Southerner in fact (although many in the South saw him as sympathetic to slaves). It would have been obvious that he would take the country in a different direction in Lincoln's absence. And he did, oh so miserably. Lyndon Johnson was a very different kind of politician than Kennedy was. Again, it would be obvious to see the country on a different path in Kennedy's absence. And after Kennedy, the country took a different path. But I find extreme safety in this regard in having Joe Biden as Vice President. Biden is a real stand up guy who is much more fit for the presidency than Andrew Johnson or LBJ was in my opinion. Although LBJ had been a star in the Senate he lacked the academic knowledge a president needs. And Andrew Johnson was a nothing Senator from Ga. Biden has been one of America's most respected Senator's for over 20 years and was elected to the Senate at 30 years old (the minimum age requirement for a Senator), And this guy cam from a very blue collar family. He did it all on his own.
But more than that, Biden shares Obama's vision for America. I find a lot of security in this. There is no other path for America waiting a heart beat away from the presidency. Assassination would accomplish very little for those who would want to see America on a different path. Plus, after the Kennedy assassinations Congress legislated standards for protection of the president and presidential candidates that were non-existent in the 1960's. This is in large part why the only assassination attempt we've seen since the 1960's has been on Reagan in 1981. That was almost 28 years ago.
So you can sleep now. When having a practical, objective look at the possibility of another presidential assassination in the coming years we see that the chances are quite low and that this cult of personality around Obama that reminds us of a Lincoln or Kennedy like figure drives our belief that past events will predict the future.