Hours after McConnell unveiled the bill Thursday, four other GOP senators said they also opposed the measure and several others expressed qualms about it.
Trump said the Democrats' theme is "resist" - which he interpreted as "obstruction" - and that "if it was the greatest bill ever proposed in mankind, we wouldn't get a vote" from them.
"We've a very good plan", Trump said in an interview broadcast Sunday.
The Senate's 142-page proposal, worked out in secret by a group led by McConnell, aims to deliver on a central campaign promise of President Donald Trump to undo former President Barack Obama's signature healthcare law, which has provided coverage to 20 million Americans since it was passed in 2010.
Johnson, one of five GOP senators who has announced opposition to the bill as written, said there's not "enough time" to review and improve it before a planned vote Thursday - just one week after the secretly drafted bill was made public. "Look forward to making it really special!"
The Senate plan repeals the Affordable Care Act's individual mandate, slashes federal support of Medicaid and eliminates taxes on the wealthy and insurers that now help pay for care for the poor.
GOP senator: 'No way' health care bill should move forward
The bill proposes phasing out federal funding to states that had been used to expand the program under the Obama administration. Senate Minority Leader Chuck Schumer (D-Brooklyn) will continue to fight the legislation which he has called "heartless".
In an appearance on the ABC News program "This Week", Collins said she has serious concerns about the cuts the bill would make to Medicaid and how that would affect the most vulnerable older Americans. McConnell and other leaders, meanwhile, are trying to rally support for a vote on the bill this week, but may be short of the support necessary to pass it. "That's not going to happen with us".
"In this form I will not support it", he said.
Then he criticized two prominent Democratic senators. "I have a hard time believing my Wisconsin constituents or even myself will have enough time to evaluate this for even a motion to proceed. let's not rush this".
In a visit to his home state Capitol Friday, Pennsylvania's senior US Senator Bob Casey called the bill "obscene".
He said his clinic mostly serves Medicaid families and kids. Rob Portman and Shelley Moore are concerned cuts to Medicaid would hurt the fight against opioid addiction by limiting low-income people's access to addiction treatment.
Expansion Draft and Awards Show in Vegas
The players who have already arrived in Vegas realize that although they're starting over, they aren't starting from scratch. It's not as if the Golden Knights were able to draft a team that would be able to compete against the Pittsburgh Penguins.
Scalise's Shooter Appears to Have Acted Alone, FBI Says
Tim Slater, the special agent in charge of the Washington FBI office, also said during a news conference Wednesday that James T. Hodgkinson bought the guns in April, after Trump was elected, Slater said. "The guy was very cordial", the sheriff said.
How Messi nearly became a Real Madrid player
But even for those who think otherwise, at least know deep within that Lionel Messi is a great footballer. But I was about to live in Madrid", Gaggioli was quoted as saying by Globoesporte , according to ESPN.
Police blame road rage for killing of teenage Muslim girl
But, contrary to those circumstances, Fairfax County authorities say that the murder is not being investigated as a hate crime . The teen along with her friends was on their way back home after visiting a fast-food restaurant when the incident took place.
Italy giving 5.2B euros in resources to keep 2 banks open
Most high-grade euro zone bond yields were unchanged on Monday, with 10-year German bond yields edging lower to 0.25 percent. Share with Us - We'd love to hear eyewitness accounts, the history behind an article, and smart, constructive criticism.
Faedo pitches Florida into CWS Finals
Gilbert has been used mostly in relief but is being pressed into the starter's role because of a forearm injury to Eric Walker. Dyson threw five shutout innings in the Super Regional clincher against Wake Forest - by far his longest game of the season.
U.S. key interest rate highest since 2008
On top of the rate hike, the FOMC said it will begin the process this year of letting some of its balance sheet portfolio run off. The US Federal Reserve raised rates for the second time this year, bringing the key interest rate up to 1.25 percent.