Congressional Republicans are out manoeuvring the Democrats by first repealing the funding for Obamacare. If they tied a successor health insurance scheme to the repeal of Obamacare, as suggested by their opponents, the Senate Democrats could filibuster this to death.
The Senate Republicans can use a reconciliation device to sidestep a filibuster of the defunding of Obamacare and pass the repeal with a simple majority vote. An attempt to repeal the remaining regulatory structure of Obama care would be subject to a filibuster. A filibuster can be overturned only with 60 votes.
By adopting a sequential approach to the repeal of Obamacare, the Senate Democrats are cornered. They can hardly filibuster attempts to replace a defunded Obamacare with more federal assistance to those on low incomes and with pre-existing conditions.