With half of the debate completed in the U.S. Senate on a House-passed bill to overhaul the Obama health law, Republicans have yet to reveal the details of what may be the only GOP option that can get a majority of votes, a streamlined measure which would change only a few provisions of current health law.

"I don't know what the "skinny" repeal looks like," said Sen. Bob Corker (R-TN) to a group of reporters, as he acknowledged doing the bare minimum on health care might be about the only way to keep GOP options open on changes to Obamacare.

"What you're really voting on is to try to keep the discussions alive between the House and Senate," Corker told reporters.

The way the "skinny" Republican option has been described in recent days is this:

+ Zero out the tax penalty on the individual mandate (note - this does not "repeal" the mandate - it just reduces the penalty to $0).

+ Zero out the employer mandate penalty

+ Repeal the medical device tax.

But there were rumblings on Wednesday that the details of the plan would have to be fiddled with, leaving GOP Senators in the dark on what they might be voting on late on Thursday night, or Friday.

"I want to see what it says; I don't know what it says - no one knows what it says yet," Corker said.

"All of this right now is procedural setup to get to an end that none of us are certain what it's going to look like,” said Sen. Johnny Isakson (R-GA).

"I'd rather comment when we see it actually formulated," said Sen. Shelley Moore Capito (R-WV) of the "skinny" Senate bill.

Down at the other end of Pennsylvania Avenue, President Trump was continuing to press GOP Senators for action, using his platform on Twitter to make one more direct appeal on Thursday morning.

But as the day began, it wasn't clear whether there would be 50 Republican votes for any GOP health plan in the Senate - skinny or not.

For seven years, many Republicans and conservative groups have pushed a story line that wasn't completely true about the Congressional debate on the Obama health law - that few hearings were held, that the bill text was kept a secret until the bitter end, that the House and Senate votes were done in the middle of the night, and more.

Having covered the legislative battle over the Obama health law, many of those criticisms weren't entirely accurate - but the irony right now is that the GOP may be following a health care script in 2017 which mirrors many of their own complaints from 2009 and 2010.