Reid previously warned that any changes to the Senate's version by the House would result in at least the start of a government shutdown because of the time it would take to reconsider the proposal.
Republican Rep. Michael Grimm of New York said Saturday a "slight" shutdown could occur due to the little time left to pass a short-term spending plan for the new fiscal year that starts Tuesday.
"I'm hoping no, but just look at the timing," Grimm said, laying out a scenario in which the political wrangling leads to last-minute deliberations on Monday and beyond.
The prospect of a government shutdown caused by GOP tactics irked the longest serving member of Congress in history, Democratic Rep. John Dingell of Michigan, who said in a statement that "this once-deliberative body has been taken over by knaves and know-nothings, content with putting partisan politics ahead of the American people."
"I've said before that I believe that this current Congress would be incapable of passing the Ten Commandments or even the Lord's Prayer, and today's actions have only further galvanized that belief," said Dingell, who was first elected in 1955 and is serving his 30th term.
The legislative hot potato involving the spending plan began last week when the House stripped Obamacare funding from the proposal it sent to the Senate.
On Friday, the Senate voted on strict party lines to restore the Obamacare funding and send the measure back to the House.
That left Boehner with the choice of urging his divided Republican caucus to join Democrats in passing the Senate plan or to yield again to the tea party wing that seeks to undermine Obamacare.
Cruz loses filibuster bid
The Senate began its votes Friday by easily overcoming a filibuster led by GOP Sen. Ted Cruz of Texas against the spending plan. Cruz waged a 21-hour floor speech this week against Obamacare, but 25 more moderate Republicans rejected his tactics in voting with Democrats on Friday to move ahead on the measure.
Meanwhile, Democrats facing re-election next year in conservative-leaning states such as Mark Pryor of Arkansas, Mark Begich of Alaska, Mary Landrieu of Louisiana and Kay Hagan of North Carolina all resisted Republican pressure to buck their party over the Obamacare funding.
Responding to the GOP tactics, Obama said Friday that new exchanges for private health insurance under the reforms will open next week as scheduled -- even if there is a government shutdown.
"The House Republicans are so concerned with appeasing the tea party that they have threatened a government shutdown or worse unless I gut or repeal the Affordable Care Act," Obama said, adding: "That's not going to happen."
Democratic Sen. Barbara Mikulski of Maryland said the goal of the short-term spending measure was to provide time to work out a broader spending plan for the rest of fiscal 2014 that would ease the impact of forced cuts to the military and other government programs.
House GOP split
Republican leaders in both chambers don't want a shutdown now over the spending issue, for political and negotiating reasons.
They fear the optics of Republicans being blamed for a shutdown, and also want to exert as much leverage as possible for the GOP's agenda at the upcoming deadline to raise the federal debt limit.
However, Boehner needs backing from the 40 or so tea party conservatives in the House in order to have a spending plan pass with full support from his Republican caucus.
The tea party opposition to the Senate version would mean it could only pass the House with support from all Democrats and some Republicans, which would further weaken Boehner's already shaky leadership of his caucus.
Tea party conservatives want to halt Obamacare now, just as full implementation of its individual health care exchanges begins in the new fiscal year starting Tuesday.
More moderate Republicans, such as veteran Sens. John McCain of Arizona and John Cornyn of Texas, criticize the strategy of tying a government shutdown to undermining the health care reform law passed by Democrats in 2010 and upheld by the Supreme Court last year.
Debt ceiling deadline
The shutdown showdown comes a few weeks before another fiscal deadline -- the need to raise the nation's debt ceiling so the government can pay all its bills.
Treasury Secretary Jack Lew said this week the limit on how much the government can borrow must be increased by October 17 or the nation could be technically in default.
Analysts warn of severe economic impact from any doubt cast over whether the United States would fail to meet its debt obligations. A similar bout of congressional brinksmanship over the debt ceiling in 2011 led to the first-ever downgrade of the U.S. credit rating.