Let's begin with the obvious.
Every law breaker who has threatened a Member of Congress ought to be arrested, prosecuted, convicted and imprisoned. There is no place in a free country for the politics of violence or intimidation.
The fanatics of both the far, far left and the far, far right have bedeviled American politics for many generations. MSM would be well advised not to give them publicity, and the usual rule for public figures and especially public officials is to never publicize threats as the publicity only engenders more threats.
Now to the not-so-obvious-to-the-Manhattan-Beltway media elite.
The attention being paid to the cranks and the nuts serves a political purpose of the mere far left, however, so it will continue. This is part of the effort to delegitimize and marginalize the exploding anti-growth-of-government movement. This deeply-felt concern over the viral expansion of the public sector is what has driven the Tea Party Movement, and it is also what will power the pummeling Democrats will receive at the polls in the fall.
In the blink of an eye, just as the federal government was swallowing whole the American health care system, it burped and then tossed down the student loan business. This follows the digestion of most of the American car business and the $800 billion "stimulus" that wasn't. Jabba-the-Fed is feeding.
Americans are stunned by the rapacity of the Democrats. The vast, vast majority of the objectors are mainstream and often previously apolitical Americans. Many are long time conservative activists. A handful of nuts have infiltrated their numbers, and the usual media suspects choose to focus on the crazies and not the millions. Many of these MSMers fretting over the rise of the fanatics use the term "Tea Baggers," which is itself an assault on civil discourse. Or they sneer at rallies which require actual commitment of time and resources, or at hand-made signs that suggest a familiarity with the Federalist Papers. They find red-white-and-blue clothing amusing. Then they turn to cluck at how standards of debate have declined in the House. Very amusing.