* Marathon attack on Obama's signature achievement
* Possible government shutdown looms in background
* Cruz must yield to Senate vote later in the day
By Thomas Ferraro and David Lawder
WASHINGTON, Sept 25 (Reuters) - U.S. Republican Senator Ted Cruz slogged into the second day of his marathon attack on Obamacare from the Senate floor on Wednesday, showing almost no signs of relenting after speaking for more than 17 hours.
Standing in a nearly empty Senate chamber, Cruz made his case to deny funding to implement President Barack Obama's landmark overhaul of the U.S. healthcare system, arguing that it is hurting the economy.
"I will confess, as we sit here a little bit before 7 a.m., I'm a little bit tired," the Texas senator said in the waning hours of his effort on the Senate floor.
But Cruz still found the energy to compare the healthcare law to the villain in the "Friday the 13th" horror films.
"Obamacare is the biggest job-killer in this country and when Jason put on his hockey mask and swung that machete, boy there was carnage like nothing else," Cruz said.
On Oct. 1, a major component of Obamacare goes into effect as individuals are allowed to begin signing up for health insurance under the government-backed program.
Oct. 1 also is the start of the government's new fiscal year. Having failed to pass the 12 regular appropriations bills that fund government activities in fiscal 2014, Congress is now in the uncomfortable situation of either approving a temporary emergency spending bill or forcing widespread shutdowns of federal agencies.
Cruz's 45 Republican colleagues in the Senate also oppose Obamacare, arguing that burdensome requirements are encouraging employers to reduce their workforce. But most of them have shunned Cruz's desire to hold up government funding - thus risking a shutdown of federal agencies next Tuesday - in an attempt to gut the law.
Elected last November, the firebrand of the conservative Tea Party movement at times strides through the Capitol in cowboy boots. But on Wednesday morning, his feet were clad in tennis shoes. In black, they matched his suit.
"Obamacare isn't working," the Texas Republican said in between stories about the struggles of his Cuban immigrant father and reciting Doctor Seuss verse. A professed carnivore, he recounted the tribulations of Christmas dinner with his future wife's vegetarian family.
'WHAT A SCOUNDREL I AM'
Only a dozen or so of the chamber's 100 senators showed up for any of Cruz's marathon, but the televised debate is sure to boost the profile of this likely 2016 presidential candidate.
Cruz began talking at 2:41 p.m. (1841 GMT) on Tuesday. His performance had the look of a filibuster, a procedural hurdle used to block legislation. Except in this case, it won't.
Under Senate rules, Cruz must yield the floor by noon (1600 GMT) on Wednesday for a procedural vote that will start the Senate toward passage of the bill to keep government agencies funded through Nov. 15 - including Obamacare money.
In the early hours of Wednesday, Cruz was joined on the Senate floor only by Republican Senator Mike Lee of Utah, who provided him with short breaks. Lee and Cruz spent the summer whipping up conservative anger against the healthcare law.
As dawn approached, Senator Marco Rubio of Florida, also a Tea Party conservative, took the lectern, giving Cruz a break, which he used to stretch with knee bends in the chamber.
Polls show most Americans oppose the health care law despite its goals of providing healthcare coverage to millions of uninsured people, but even more oppose a government shutdown.
Early in his effort on Tuesday, Cruz talked about his father "flippin' pancakes," making "green eggs and ham," "the travesty of Obamacare," and, proudly, about his unpopularity among many fellow Republicans. For more see
"I now pick up the newspaper to learn what a scoundrel I am" practically every day, he said.
"He is using the floor to promote himself," Democratic Senator Claire McCaskill said Wednesday on MSNBC's "Morning Joe."
The Republican-controlled House of Representatives last week passed a version of the spending measure that denied funds to Obamacare. Democrats plan to strip the Obamacare provision from the Senate version.
With time running short, the House will have to decide whether to go along with the revised bill or find a compromise with the Senate.
Republicans uniformly want to repeal Obamacare. But many see that as a political impossibility as long as Democrats control the Senate and hold the presidency.
Once the battle over the government funding bill is resolved, Congress will grapple with another fiscal crisis - a possible federal government debt default unless it agrees to raise the $16.7 trillion U.S. borrowing authority next month or in early November.
Republicans are expected to place demands on any bill to increase the debt limit, including one for a yearlong delay in implementing Obamacare, which is to take effect next month.