Why are reporters helping conservative Senators avoid taking a stand?

Here's Chris Matthews, purported political expert, offering his take on the prospects for health care reform:

The way I see it, he's [President Obama] got three ways to go at this point.

One: They can challenge the Senate rules and ram through a bill with just 50 votes with the help of the Vice President to break the tie.  That's what today's lede in the New York Times suggested they're threatening to do. [Matthews later made clear he was referring to using the reconciliation process]

Number Two: They can go for a moderate bill, politically sellable to a few Republicans and get the 60 Senate votes needed for regular passage.

Three: They can go back and build a dramatic rock-'em-sock-'em liberal bill, stand ready to take the loss and blame Republicans for the failure.

Matthews is forgetting something: 60 votes are not needed for "regular passage." Sixty votes are needed to invoke cloture, at which point 50 votes (plus Biden) are all that is required for passage.

What this means is that a health care bill with a public plan could pass if some of the conservative Senators who have made noises about opposing such a plan prove unwilling to filibuster the bill, even if they don't plan on voting for it.  Joe Lieberman, for example.

The obvious meaning of this is that when a Joe Lieberman or a Ben Nelson expresses skepticism about the public plan, reporters should ask them if they will filibuster it, or allow it to come to a vote.  But that rarely happens.  Instead, reporters let those Senators off the hook, allowing them to get away without taking a strong stand.  

Which, of course, is exactly what some of them want: to avoid taking a stand.  Joe Lieberman may not want to vote for a public plan -- but he probably doesn't want to tell Connecticut voters he'll filibuster, either.  He's probably hoping he never has to; that his statements of opposition will ensure it never comes to a vote.  That's a perfectly valid, if not terribly brave, approach for him to take.  But there is absolutely no reason reporters should play along with it.  It's their job to press politicians to take a stand, not help them avoid doing so.