Republicans in Congress are grilling Google CEO Sundar Pichai over allegations that the search giant is biased against conservative media and websites.

Democratic Rep. Zoe Lofgren of California gave Pichai a chance to explain why there's no conservative bias.

She asked why a picture of President Donald Trump comes up when you Google image search for the word "idiot."

"We don't manually intervene on any particular search result," Pichai said.

Google CEO Sundar Pichai is testifying before the House Judiciary Committee on Tuesday, and amid questions on competitive dominance, Chinese censorship, and privacy, Republicans on the committee have focused on allegations of conservative bias.

They allege that Google's search results are biased and that Democrats who work at the search giant choose liberal websites over conservative views for prime placement on Google services like search.

Democrats on the committee pushed back, and Rep. Zoe Lofgren of California, who represents the district including San Jose, gave Pichai a chance to explain at length why Google search results aren't biased.

Her question involved President Donald Trump.

Read more: Opinion: Donald Trump is right about Google — but for the wrong reason

"Manipulation of search results — I think it's important to talk about how search works," Lofgren said. "Right now, if you Google the word 'idiot,' under images, a picture of Donald Trump comes up. I just did that."

She's right. Here's a search in an incognito window:

Screenshot

"How would that happen? How does search work so that that would occur?" she asked.

Here's Pichai's full response:

"We provide search today for — anytime you type in a keyword, we as Google, we have gone out and crawled and stored copies of billions of webpages in our index. We take the keyword and match it against webpages and rank them based on over 200 signals, things like relevance, freshness, popularity, how other people are using it. And based on that, at any given time, we try to rank and find the best results for that query. Then we evaluate them with external raters to make sure, and they evaluate it to objective guidelines, and that's how we make sure the process is working."

Lofgren followed up: "So it's not some little man sitting behind the curtain figuring out what we're going to show the user — it's basically a compilation of what users are generating, and trying to sort through that information."

"Last year we served over 3 trillion searches. Just as a fact, every single day, 15% of the searches Google sees, we have never seen them before," Pichai said. "So this is working at scale. We don't manually intervene on any particular search result."

During the hearing, several Republicans on the committee, including Rep. Lamar Smith, said there was "political bias baked into" Google's culture.

Steve Chabot, a Republican from Ohio, said he needed to go to the third or fourth page of search results to find positive coverage of the bill introduced last year to repeal the Affordable Care Act.

"You had to go deep into the search results," Chabot said. "I know Google's attitude, 'The algorithm made us do it,' but I don't know that I buy that."

Watch the full exchange below: