Republican lawmakers displayed the party’s growing distrust toward Google, raising a broad array of tough questions on the search giant’s market power, plans to relaunch service in China, and whether the site suppresses conservative content. At the core of their questions was a concern over the company’s commitment to free expression. “All of these topics — competition, censorship, bias and others — point to one fundamental question that demands the nation’s attention,” said Representative Kevin McCarthy of California, the House Republican leader. “Are America’s technology companies serving as instruments of freedom or instruments of control?” “Because a free world depends on a free internet, we need to know that Google is on the side of the free world,” Mr. McCarthy said. Representative Robert W. Goodlatte of Virginia, the Republican chairman of the Judiciary Committee, highlighted the importance of scrutinizing Google because of the company’s market power in search, cloud-based email and its Android mobile operating system. Mr. Goodlatte also raised concerns that the liberal-leaning political biases of employees may also affect filtering decisions for its search engine. He mentioned a leaked video the day after the 2016 presidential election showing top officials lamenting the victory of President Trump. “This committee is very interested in what justifies filtering,” Mr. Goodlatte said. “Given the revelation that top executives at Google have discussed how the results of the 2016 elections do not comply with Google’s values, these questions have become all the more important.” Mr. McCarthy is among several Republican members who have made online political bias a talking point in campaign fund-raisers. Claims of anti-conservative bias within the technology of Google, Facebook and Twitter have been disputed by numerous technologists and academics. Democrats had their own set of tough questions for Mr. Pichai on privacy and the company’s competitive practices. But they also expressed frustration with the political bias claims. “I must dispense with the complete illegitimate fantasy dreamed up by some conservatives that Google and other platforms have anti-conservative bias,” said Representative Jerrold Nadler of New York, the top Democrat on the committee. Praise for Google as Well. Officials were expected to be merciless for Mr. Pichai’s first appearance before Congress. When he declined to appear in a Senate hearing in September, lawmakers called the act “arrogant,” and they put out an empty chair in his absence. Though lawmakers asked Mr. Pichai a variety of pointed questions, they also lauded Google as an American icon. “Your company should really be held out as a success story of America’s free enterprise system,” said Representative Keith Rothfus, a Republican of Pennsylvania. “Despite the nature and scope of today’s hearing, Google is still the story of the American dream,” Mr. Goodlatte said. “We do not want to impose burdensome regulations on your industry,” said Representative Mike Johnson, Republican of Louisiana. Going into a third hour of the hearing, Republicans offered little detail on how they would follow up on concerns about privacy and anti-conservative bias. Democrats, in large part, defended the company of political bias claims. Representative Ted Lieu, Democrat of California, said negative news coverage of members like Representative Steve King, Republican of Iowa, were perhaps the result of his views on immigration. “Don’t blame Google or Facebook or Twitter, consider blaming yourself,” Mr. Lieu said. During Mr. Pichai’s testimony, the first question from Mr. Goodlatte was about whether consumers understand the frequency and amount of location data that Google collects from its Android operating system. It was the first of many questions directed at Mr. Pichai about the collection of location data and apps that run on Android smartphones, some citing an investigation by The New York Times. Mr. Pichai ...