In a marathon markup meeting that lasted all night, the House Judiciary Committee approved five of the six sweeping antitrust bills that take aim at Big Tech and attempt to reel in the giants’ power.

But the lengthy debate that began Wednesday and did not finish till Thursday morning illuminated the fissures within both parties as tech companies continue lobbying lawmakers, and some California delegates — whose districts encompass many tech headquarters — voiced skepticism.

The committee was set to debate the sixth bill Thursday morning, more than 24 hours after the markup began.

The bills, which have some bipartisan support, target the far-reaching power of Big Tech, especially Apple, Amazon, Facebook and Google. The committee spent the first several hours debating the two least controversial bills — a measure that would update merger filing fees, and another that deals with venues for antitrust suits brought by state attorneys general.

The bills with more substantial changes passed throughout the night, including a bill to prevent tech giants from buying rising competitors; one to prohibit big tech companies from giving their own products and services preference over those from competitors; and another to make it easier to use products from different tech companies together.

The last, and possibly most contentious, would enable federal regulators to sue to break up large tech companies when their role as operator of a platform presents an “irreconcilable conflict of interest” in their other lines of business. That could spell trouble especially for Amazon — which operates a major e-commerce marketplace where it also competes as a seller of its own goods — and potentially for Google — which ranks videos in its search engine while also running its own major video service, YouTube. (Amazon founder and CEO Jeff Bezos owns The Washington Post.)

Big Tech is making a full-court press in lobbying lawmakers to defeat the bills, according to reporting in Gizmodo and the New York Times. The push is made clear in public calls from industry trade organizations and the companies themselves.

The Times reported Apple CEO Tim Cook called House Speaker Nancy Pelosi (D-Calif.) to say the bills would harm innovation. Apple did not immediately respond to a request for comment about the call.

Apple issued a report Wednesday morning outlining what it sees as the perils of letting consumers “sideload” apps, a process enabling apps to be downloaded on Apple products without going through the company’s App Store. Critics have argued that Apple’s control of the App Store, and especially its practice of taking a cut of in-app purchases, threatens smaller competitors.

The iPhone maker also sent a Tuesday letter to the committee, saying the bills would restrict consumer choice and would not promote competition.

Similarly, Amazon released a statement from vice president of public policy Brian Huseman saying the bills “would have significant negative effects on the hundreds of thousands of American small- and medium-sized businesses that sell in our store.”

Google’s vice president of government affairs, Mark Isakowitz, said the bills raise privacy concerns and “damage the way small businesses connect with consumers.” And Facebook spokesman Andy Stone said antitrust bills should “not punish successful American companies.”

Some of the onslaught of lobbying has been pretty clumsy, said a staffer to a Democratic member of the committee who spoke on the condition of anonymity because they were not authorized to speak publicly.

“For one thing, I think the clearer the tech opposition to these bills, the easier it has been to make the case that they are exactly what we need,” the staffer said.

The package has the support of Judiciary antitrust subcommittee chairman David N. Cicilline(D-R.I.), who led an exhaustive House investigation into big tech companies last year that preceded the bills.

“Amazon, Apple, Facebook and Google are gatekeepers to the online economy,” Cicilline said early in the committee markup Wednesday. “They bury or buy rivals and abuse their monopoly powers — conduct that is harmful to consumers, competition, innovation and our democracy.”

He is supported by a number of both Democratic and Republican lawmakers, though the parties are not consistent in their support.

Some conservatives want to curtail big tech’s power, just not in the same way. The day before the markup, Rep. Jim Jordan (R-Ohio) partnered with former Trump chief of staff Mark Meadows on an opinion piece for Fox News calling for Republicans to be skeptical of the bills.

“These Democrat bills will only make things worse,” they wrote. “If you think Big Tech is bad now, just wait until Apple, Amazon, Facebook and Google are working in collusion with Big Government.”

Democrats have approached antitrust legislation by focusing on tech companies' growing economic concentration, while Republicans have focused on their concerns that tech companies have stifled conservative voices online.

At the markup, three members from California, where many of the tech giants are headquartered, and all are large employers, also voiced skepticism.

“In my district, small businesses depend on services provided by these tech companies,” Rep. Lou Correa (D-Calif.) said in a statement. “Amazon has opened a distribution center and is looking to open a few more. These are good-paying jobs with benefits.”

Rep. Eric Swalwell (D-Calif.) said he would not support three of the more sweeping bills.

“In my district alone, I represent thousands — likely in the five digits — of employees affected by the proposed laws,” he said in a statement. “It is these people whose jobs, families, and livelihoods I was elected to protect — and must advocate for today.”

Rep. Zoe Lofgren (D-Calif.) said before the markup began that four of the bills as introduced could create more harm than good. She introduced several amendments during the markup.

“While I share the desire to reform digital markets and increase competition, as drafted, the bills fall short and will create more harm than good for American consumers and the U.S. economy,” she said in a statement.

She focused on allowing the companies to protect privacy and moderate content — echoing similar sentiments to what a few of the companies argued in their statements of opposition to the measures.

Tyler Pager contributed to this report.