Investor’s Business Daily says CBS News needs to be held accountable for their use of forged documents—and subsequent stonewalling.

Could it be that CBS and Rather wanted to take Bush down a peg — especially given the questions about John Kerry’s Vietnam service raised by the Swift Boat Veterans for Truth?

And could it be that CBS and Rather let their well-documented political leanings overrule their journalistic sense? Have they become just another hack voice in the political game?

Sadly, the answer seems to be yes. CBS’ bias made it vulnerable to a hoax that fit nicely with the network’s left-leaning culture.

Yet despite the evidence, Rather doesn’t sound contrite — or even worried — about either the validity of the documents or CBS’ credibility. “I know that this story is true,” he said. “I believe that the witnesses and documents are authentic.”

For its part, CBS says it won’t look further into the memo’s authenticity. “Contrary to some rumors, no internal investigation is under way at CBS News, nor is one planned. We have complete confidence in our reporting and will continue to pursue the story.”

Given the mounting evidence, it sounds like a stonewall to us.

Journalists need to own up to their mistakes publicly — and not on page A32, near the truss ads, or on Saturday evening newscasts, when few people are watching.

It now appears CBS made a grievous mistake or knowingly relayed false information. If so, what credibility does it have left? Even an on-air correction won’t undo the damage.

CBS would go a lot further in restoring its credibility if it at least checked into the source and authenticity of the memos.

If it’s shown that Democrats or the Kerry campaign are the source — as suggested by comments to the American Spectator by an unnamed Kerry staffer — CBS better say so.

If the documents prove to be forgeries, resignations from Rather and CBS News President Andrew Heyward would be in order — along with a sweeping review of ethical practices at a once-proud news organization.