The Republican nominee lashes out in the wake of his poor debate showing and hints at more attacks on the Clintons’ marriage

Donald Trump has gone on the offensive after his underwhelming debate performance by criticizing debate moderator Lester Holt as biased and accusing Google of a conspiracy to rig search results in favor of Hillary Clinton.

He also had surrogates attack his Democrat rival for her husband’s infidelities while suggesting she wants to “strip [the United States] of its status as a sovereign nation”.

The Republican nominee launched the latest salvo of attacks in an interview with Fox News’s Bill O’Reilly where he claimed Holt “was much, much tougher on me than he was on Hillary”. Trump said that while initially “I said good things right after the show” he had changed his mind about Holt’s performance “after seeing the way he badgered and even the questions I got”.

In particular, Trump expressed his discontent over the fact that Holt asked him “the birther question” in Monday’s debate. Trump had long falsely claimed that Barack Obama was not born in the United States, an accusation widely considered to be a racist dogwhistle. Although Trump only recently acknowledged that Obama was born in the United States in an event at a Washington hotel, he falsely blamed Hillary Clinton for the conspiracy theory’s origin. He since said that he only acknowledged Obama’s actual birthplace in order to “get on with the campaign”.

Trump also introduced a new conspiracy theory to the campaign on Wednesday night when he accused Google of somehow colluding with Hillary Clinton’s campaign. “Google search engine was suppressing the bad news about Hillary Clinton,” the Republican told a cheering crowd of supporters in Waukesha, Wisconsin. Neither Google nor the Trump campaign responded to requests for comment on this accusation, which seems to stem from a report in Sputnik News, a Russian state propaganda outlet. The reference to Google did not appear to be ad libbed as it was in Trump’s prepared remarks.

Also, at the rally, Trump unveiled a new accusation towards Clinton, whom he has repeatedly attacked as “a globalist”, by saying she was a “vessel for special interests ... who want to strip [the United States] of its status as a sovereign nation”. Although the former secretary of state has long favored immigration reform as well as number of free trade agreements, there is no evidence that she has ever supported stripping the United States of its sovereignty.

However, Clinton is facing scrutiny over her complicated marital history. After Trump publicly congratulated himself for not bringing up former president Bill Clinton’s past infidelities in Monday’s debate, his campaign has cited them in talking points in an attempt to rebut past crude statements about a beauty queen.

Alicia Machado, Miss Universe weight-shamed by Trump, speaks out for Hillary Clinton Read more

The statements about former Miss Universe Alicia Machado, which included calling her “Miss Piggy” for her weight and “Miss Housekeeping” in reference to her Hispanic heritage, were brought up by Hillary Clinton in Monday’s debate. Trump owned part of the Miss Universe pageant at the time.

In talking points distributed to Trump surrogates on the topic, they were told to change the topic to Monica Lewinsky and included the line “Mr Trump has never treated women the way Hillary Clinton and her husband did when they actively worked to destroy Bill Clinton’s accusers.” In interviews on Wednesday, Trump surrogates repeatedly brought the subject up. Trump himself tried to cast himself as an ally of Machado in an interview with O’Reilly. He repeatedly said “I saved her job” and added in seeming regret: “I helped somebody and this is what you get for helping somebody.”

Clinton spent the day campaigning with former rival Bernie Sanders in New Hampshire. The two tried to appeal to millennial voters by repeatedly touting Clinton’s proposal to reduce the cost of college tuition. Clinton is facing declining enthusiasm among millennial voters who were one of the key groups in the winning coalition forged by Obama in his election victories. According to a recent poll conducted by ABC/Washington Post only 49% of voters under the age of 40 said they were likely to vote in November. A similar poll in 2012 put that number at 71%. The Democratic nominee also held two fundraisers on Wednesday, one of which featured an appearance from Massachusetts senator and progressive Elizabeth Warren.

The leading third party alternative to Clinton and Trump suffered his own embarrassment on Wednesday. Gary Johnson, the Libertarian nominee for the White House, was unable to name a single foreign leader he admired in an interview with MSNBC’s Chris Matthews. He referred to his inability to come up with a single name as “another Aleppo moment”. This was a reference to a televised interview several weeks ago when the former two-term governor of New Mexico, having been asked “What would you do if you were elected, about Aleppo?” on MSNBC’s Morning Joe, responded with the question “What is Aleppo?”. Johnson seemed unaware of the Syrian city which has been long under siege in the midst of that country’s civil war and the site of numerous atrocities by the Assad regime and its allies.

The candidates will return to the campaign trail on Thursday by meeting voters in states that they are long familiar with from the primaries. Clinton is holding an event in Iowa while Trump returns to the trail in New Hampshire.

• This article was amended on 29 September 2016. An earlier version said incorrectly that Gary Johnson “came up empty when asked ‘What is Aleppo?’ on MSNBC’s Morning Joe”.