House Minority Leader Nancy Pelosi urged Democrats in an "emergency request" to hold town hall meetings and press conferences and to fire off a "tweet storm" this week to help kill the momentum building behind a last-ditch GOP plan to reform Obamacare that was written by Sens. Lindsey Graham of South Carolina and Bill Cassidy of Louisiana.

"It is all hands on deck to defeat the latest version of Trumpcare, Graham-Cassidy," Pelosi wrote to House Democratic rank-and-file lawmakers Tuesday.

Democrats, Pelosi said, "will be fully mobilized to amplify the organizing of outside groups and lift up the voices of families who would be devastated by Trumpcare."

Pelosi said this coming Saturday would be a "day of action," against the GOP measure. She urged Democrats to participate in a Tuesday afternoon "tweet storm" against the legislation.

The Graham-Cassidy legislation is scheduled for hearings in the Senate next week and is on track for a possible vote before a Sept. 30 deadline.

The sudden support for the repeal-replace effort has left Democrats scrambling to try to undermine the measure, which would replace Obamacare with block grants that would give states the power to determine Obamacare's fate and financing.

If the Senate GOP is able to pass the measure with 51 votes, circumventing a filibuster by Democrats, House Republicans appear poised to clear it for President Trump's signature, which would significantly alter the signature achievement of the Obama administration and the four-year reign of the Democratic majority in Congress that began a decade ago.