The Post reports:

"A crucial GOP senator is raising questions about the bill after finding out that it includes a tax break that could financially benefit him and politically tarnish him.

"Sen. Bob Corker, R-Tenn., says he wasn't aware of this new tax break for wealthy real estate developers like him, but the left is whacking him for initially withholding support yet later backing the bill around the same time that this provision was included.

"Corker, who is retiring next year, has denied he had anything to do with this provision. But if the senator feels that he can't vote for the final tax bill because of perception fears, the whole legislation could fall apart the same week that Republicans had hoped to finally pass it."

We have no reason to doubt Corker, who says he was unaware of the provision. CNN explained, "According to [Sen. Orrin] Hatch, Corker and his staff never contacted the Senate Finance Committee about including the provision. Hatch said that instead, the provision was merely a result of combining the House and Senate tax bills, which both structured taxes for pass-through entities like real estate LLCs differently."

However, Corker's alleged mendacity is not the issue. Rather, the question now is: Knowing that this provision is included and that the bill is just as fiscally irresponsible as the version he voted against, how could he vote for the bill anyway? (As for Hatch, it seems he put the measure into the bill to benefit the real estate industry, which has lavishly contributed to his campaigns. "Experts familiar with the specific workings of how the tax break is formulated said that while there are some general similarities between the House bill and the conference report, Hatch sculpted a brand new provision for the final bill — one that was not in the previous versions of the legislation.")

Over several days we've asked Corker's office that question and have yet to get a responsive answer. "I didn't put the real estate tax grab in there" or "I didn't know the real estate tax grab was in there until the press told me" does not cut it. It's curious to say that he was concerned enough about the debt to vote no on the bill last time but not this time. What happened between now and then?

We can speculate on the reasons — political peer pressure, self-interest, keeping a political future alive, the potential absence of two GOP senators due to health concerns, etc. Politico reports:

"'On one hand, you had the deficit issue. On the other hand, you had the economic growth issue,' Corker said. 'I took a long walk on Friday morning and just decided that from the standpoint of, if I were the deciding vote on this ... is our country better with this or not better with it? And I feel that we are.'

"Corker, who had also met with Treasury Secretary Steven Mnuchin to discuss the tax measure, spent considerable time on the phone with local business leaders in his home state and other experts to weigh the pros and cons of the bill, Corker said."

But it is up to Corker to explain to the country and his constituents why he disagrees with virtually every independent assessment saying long-term growth will not make up for the increase in the deficit; why he shouldn't force the Senate to start anew with a revenue-neutral corporate tax bill; why the offending real estate break should remain in the bill; and why he thinks it's necessary to skew so much of the tax relief to the super-rich. Simply saying "growth" doesn't explain why one would vote for this bill.

Likewise, Sen. Susan Collins, R-Maine — who recently vowed to stay in the Senate to continue to be "a bridge between the two sides ... [when] fewer and fewer senators enjoy playing that role" — could have led the way in forcing senators to work on a bipartisan bill, one more fiscally responsible and less generous to the super-rich. Instead of being a bridge to Democrats, she allowed Republicans to dig in their heels.

She has been taking a pounding from health-care advocates as well as local and regional media. On Monday, the Bangor Daily News pointed out:

"Versions of three amendments pushed by Collins are in the package that would allow taxpayers to deduct up to $10,000 in property taxes, reducing a medical expense deduction threshold and allowing public and nonprofit employees to keep making catch-up contributions to retirement accounts.

"However, Republicans may not oblige Collins on another key priority: Offsetting the eventual tax bill's repeal of the Affordable Care Act's mandate that individuals buy health insurance or pay a penalty with the passage of two other bills that could offset hikes in premiums caused by such a move, which the Congressional Budget has estimated at 10 percent."

In other words, Collins' central promise to protect health-care exchanges went overboard in favor of talking points on growth. (In announcing her decision, a statement from her office insisted, "Senator Collins secured the commitment of Majority Leader Mitch McConnell to pass two important bills before the end of the year to mitigate health insurance premium increases caused by the repeal of the individual mandate. Senator McConnell promised to support passage of both Alexander-Murray, a proposal to help low-income families afford insurance, and Senator Collins' bipartisan bill to protect people with pre-existing conditions through the use of high-risk pools." In fact, there is zero evidence that McConnell will deliver yet — House Republicans oppose these bills, which are not included in spending bill drafts — and she's voting for the bill anyway.)

A cleaner bill with fewer hidden surprises such as the real estate provision would be more likely to promote tax fairness and growth. A bill without repeal of the individual mandate would have preserved the health-care exchanges that Collins vowed to stabilize. That Corker and Collins nevertheless chose not to stand firm but instead go with the herd stampeding toward an ill-conceived bill that was never the subject of serious, open hearings remains a mystery and source of disappointment for those who expected conviction, not collapse, when the chips were down. We can only conclude that those expectations — fed by these senators' rhetoric and self-description as "moderates" — were misplaced.

The Washington Post