HARRISBURG – At a morning rally in the state Capitol, Sen. Bob Casey urged voters to help him and other Democrats defeat the Republican Senate plan to replace the Affordable Care Act.

"In the next couple of days, into the very last hour, please keep advocating," Casey told several dozen people gathered in the Rotunda. "Please keep writing and marching and calling, and going on social media, and calling senators in other states as well as Pennsylvania. Keep going, keep pushing, because we can defeat this bill if we keep working together."

He spoke a day after Senate Republicans unveiled their long-awaited proposal to replace Obamacare, a bill their leaders hope to bring to a vote next week. With Republicans clinging to a two-seat majority in the chamber and Democrats unified against the plan, every vote will count.

Casey said debate about the bill had paid too little attention to how the proposal would affect people who get their health insurance through their employers — more than 150 million Americans.  "If you've got employer coverage, they're coming for you, too," he said. "Because if you live in a state in the future where there's a waiver, you will not get protection from preexisting conditions.

"They can still make sure that if you're pregnant, you're not going to get the kind of maternity benefits that you might need. All that will be legal if the state you live in goes with a waiver," he said. "So don't think you're in the clear because we're talking a lot about Medicaid. That's why I said this bill is bad for the whole country."

Pennsylvania's other senator, Republican Pat Toomey, was among the lawmakers involved in crafting the bill. In an op-ed article published in the Inquirer, Toomey said "the foundation of Obamacare, a dramatically enhanced federal role in health insurance, has failed to deliver on the promises of its architects."

He said the Senate proposal won't affect "the vast majority of Pennsylvanians" who get insurance through an employer, Medicare, or the Children's Health Insurance Program, but will "stabilize" the individual market used by about 400,000. And he disputed claims the bill would drastically cut Medicaid, which serves low-income Americans, saying it seeks to reform it "so it is sustainable for future generations and taxpayers." Toomey also said the proposal — a parallel bill to one that has been passed by the House — still needs to undergo extensive review and will be subject to amendments.

Toomey's stance – and his position in the Senate – has for months made him a target of protesters who gather outside his Philadelphia office. Dozens returned again on Thursday and Friday to rally against the proposed legislation.

"No repeal without a better deal!" some protesters shouted Friday morning as they held up signs at the corner of Second and Chestnut Streets.

Among them were Leah Shepperd and her husband, Jaime Alvarez. The Fishtown couple said they would not be affected by GOP plans to replace Obamacare. "'But it will affect our friends and family. I feel like the cost of uninsured people is going to eventually affect everyone," said Alvarez, 41.

Staff writer Valerie Russ contributed to this article.