I was on the premiere of John King Live on CNN last night, talking about the primary problems Michael Bennet now faces as he moves away from his commitment made only a month ago to an up-or-down vote on the public option in the Senate.

The Denver Post also writes about it this morning:

In the past month, Bennet has become the hero of progressives, after he authored a letter — signed by at least 23 other senators — to Senate leaders pressing them to use reconciliation to revive the public option.

“He didn’t put out a letter saying, ‘I support the public option except if leadership wants me to be a toady to the party,’ ” said Jane Hamsher, who runs the influential liberal blog firedoglake.com.

Not all liberal groups are challenging Bennet, however. The Progressive Campaign Change Committee, which had actively touted his push for the public-option vote, is hoping that there can be a later vote, perhaps attached to next year’s budget, said co-founder Adam Green.

But that’s not enough for Hamsher.

“He raised money, he built his list,” she said. If Bennet doesn’t offer an amendment, “he’ll look like a hack who was only in it when he thought there was nothing he could do.”

Romanoff issued a challenge to Bennet last Friday to honor his commitment, saying “where’s the ‘public option’ champion?”  Colorado columnist and radio host David Sirota added fuel to the fire, asserting that “thanks to Romanoff’s demand,  [Bennet] will have to put up or shut up. If he refuses to offer the amendment, he shows his past efforts to be kabuki theater — grandstanding for attention while refusing to actually take the steps necessary to do what he publicly claims he wants to do.”

In response, Bennet’s campaign manager Craig Hughes said that “issuing a press release is not leadership…What we’re not going to do is kill the bill to make a point.”  And Bennet spokesman Adrianne Marsh reiterated that to the Denver Post, saying “He will not recklessly sacrifice this bill while tens of thousands of Coloradans are losing their health insurance and seniors are facing critical decisions about their medication.”

But adding an amendment to the Senate reconciliation “fix” later this week cannot possibly jeopardize the health care bill, which   President Obama signed it into law at 11am this morning.  Bennet would simply be introducing an amendment to the sidecar legislation which was crafted to satisfy union demands that the excise tax be reduced.  A Medicare tax on unearned income and $22 billion that would have gone to student loan reform will make up the difference.

This latest round could fuel the already intense debate that has erupted on Colorado blogs surrounding both the Romanff-Bennet race, as well as the health care bill itself.  While 80% of all Democrats favor a public option, they are increasingly skeptical about commitments made by politicians for the purpose of manipulating online support in an attempt to harvest emails and emulate Barack Obama’s successful 2008 grassroots fundraising model.  After 65 members of Congress pledged to vote against any bill that does not have a public option, online supporters raised $430,000 in campaign donations to thank them.  Every one of them subsequently abandoned that pledge, but none except Dennis Kucinich has offered to return those contributions.

Bennet could easily get caught in the backlash.  While he maintains that a vote can be taken on the public option at a later time, such a  would require 60 Senate votes whereas the current amendment would require only 50. And as Bennet well knows, there are not 60 votes of support in the Senate for a public option.  His current actions only add ammunition to those in Colorado who have questioned the sincerity of his commitment from the start.

Romanoff’s actions could create problems for other Democratic incumbents as well.  Joe Sestak is challenging Arlen Specter for his Pennsylvania Senate seat, but Specter has maintained a steady lead in the polls after coming out aggressively for the public option.  Specter signed an October 8 letter urging the inclusion of a public option in the health care bill.  Should Sestak decide to follow Romanoff’s lead, Specter could likewise find himself on the hot seat about the sincerity of his commitment as well.

The public option challenge could not come at a worse time for Bennet, who lost the Colorado Democratic caucuses to Romanoff last week — Romanoff had 49.9 percent  to Bennet’s 41.9 percent.