Republican Senator Ted Cruz finally took his seat in the U.S. Senate at noon today after finishing a marathon speech about President Barack Obama's health-care law that lasted more than 21 hours and involved a reading of Dr. Seuss's Green Eggs and Ham.

The Texas legislator began his overnight talk-a-thon Tuesday afternoon and by 7 a.m. ET Wednesday, he confessed he was "a little bit tired." But he also said he was inspired and encouraged by the Americans who support his determined push to scrap Obamacare, as the health-care law is known.

"I intend to speak in support of de-funding Obamacare until I am no longer able to stand," Cruz, sporting running shoes with his suit, had said when he began speaking. "All across this country Americans are suffering because of Obamacare. Obamacare isn't working."

Cruz kept talking, through the night and mostly to an empty chamber, and while at times he veered off topic, he spent a lot of time on why he is opposed to the health-care law that was passed more than three years ago.

After Cruz stopped talking and the Senate began its daily proceedings, Harry Reid, the Democrat leader, said Cruz's political theatre was "interesting to watch." He also described the marathon speech as "a big waste of time."

Cruz has been leading the charge to tie de-funding the law to a spending measure, known as a continuing resolution, that has to pass through Congress in order to avoid a U.S. government shutdown next week. An agreement to keep funding the government must be reached by midnight Monday.

Republicans in the House of Representatives passed a measure on Friday that would fund the government until November — except for anything related to Obama's health-care law — and it's now in the hands of the Senate. The Democrat-controlled Senate is expected to strip out the provisions related to the health-care law and send the continuing resolution measure back to the House, potentially on the eve of next week's deadline.

It's not clear what the House will then do with it but they could have very little time to decide. Senate Minority Leader Mitch McConnell warned that extended delays could hamper the GOP-controlled House's ability to send a pared down measure back to the Senate in time to try to salvage some kind of victory, perhaps on a bipartisan proposal to eliminate a new Obamacare tax on medical devices.

Moody's warns of recession

Mark Zandi, chief economist at Moody's Analytics, said he’s concerned that more people aren’t protesting the Republican tactics.

“I hope that as we reach the debt limit we’ll hear a cacophony of people saying this is the wrong thing to do because only then will Congress act,” he said in an interview with CBC’s Lang & O’Leary Exchange

The U.S. has until Oct. 17 until it runs out of money, he said, but if the decision is left that late, markets will start to get nervous.

If the standoff is left unsolved for longer, the government has no resources to draw on.

“If you break the government, someone is not going to get paid. It’s going to be social security recipients, Medicare and Medicaid recipients and that’s going to be upsetting for the entire population. Financial markets will be roiled. Stock prices will decline. It will be a severe recession,” Zandi said.

Cruz began talking Tuesday afternoon

Cruz's marathon speech on why the health-care law is "a train wreck" and a "jobs killer" has the appearance of a filibuster, but technically it's not. He was not able to delay a procedural vote scheduled for Wednesday and had to give up the floor according to Senate rules at noon.

The speech, nonetheless, will help get Cruz in the record books as giving one of the longest talking sessions ever in the Senate.

Budget Battle Cruz

Republican Senator Ted Cruz of Texas is seen on a television screen in the Senate Press Gallery during the 10th hour of his speech on the Senate floor on Wednesday in Washington. (The Associated Press)

Cruz took control of the Senate floor at 2:41 p.m. ET Tuesday and has used a variety of tactics to pass the time, including reading messages from Twitter and reading bedtime stories to his kids. He read passages from the Bible to his daughters whom he said were watching him on TV. Cruz took some liberties with the Green Eggs and Ham text.

"When Americans tried it, they discovered they did not like green eggs and ham and they did not like Obamacare either," Cruz said while reading from the famous Dr. Seuss tale. "They did not like Obamacare in a box, with a fox, in a house or with a mouse. It is not working."

Fellow Tea Party Republicans including Senator Marco Rubio and Senator Mike Lee helped Cruz out by stepping in to speak, posing and answering questions, which allowed Cruz to give his mouth a break without giving up control of the floor. He must remain standing.

Lee discussed a childhood accident in which his foot was run over by a car driven by his father. Cruz recalled his first Christmas dinner with his future wife's vegetarian parents, which he described as "just like any other Christmas dinner except the entree never comes."

While he has some allies, there are many in Cruz's party who are not supporting the delaying tactics. They include the top Republicans in the Senate, Mitch McConnell and John Cornyn. Republicans widely oppose Obamacare but some are worried their party will take the blame if a government shutdown happens on Tuesday.

Cruz offends with Nazi reference

Cruz said he has learned that defying party leaders is "survivable," adding, "Ultimately, it is liberating," and that his long evening involved "sometimes some pain, sometimes fatigue." But he added, "You know what? There's far more pain in rolling over. ... Far more pain in not standing up for principle."

The Texas Republican caused some offence during his speech in the Senate when he equated the fight against Obamacare to the fight against the Nazis and other wars.

Republican Senator John McCain said he doesn't agree with the "inappropriate" comparison and that he made his displeasure known to Cruz.

Senator Charles Schumer said he was "appalled" when he heard the comparison, particularly as someone who lost relatives in the Holocaust. "To compare the two was absurd," he told the Senate.

He also said he was surprised Cruz read from Green Eggs and Ham.

"The moral of that story is to try things you may not like," said Schumer. "If he tasted Green Eggs and Ham, he may actually like them."

With files from The Associated Press