By Jason Lange

WASHINGTON The federal criminal charges against Donald Trump have done little to change Americans' views of the former president, based on a new Reuters/Ipsos poll completed on Monday that shows him maintaining a commanding lead in the race for the Republican presidential nomination.

The polling, which began on Friday, a day after Trump announced he had been indicted, found that 62% of respondents, including 91% of Democrats and 35% of Republicans, said it was believable that Trump illegally stored classified documents at his home in Florida.

But 81% of Republicans said the charges against him were politically motivated.

The news did not appear to dent Trump's standing in the Republican nominating contest for the 2024 presidential election. The specific charges, including obstruction of justice, became public on Friday afternoon when the indictment was unsealed.

Some 43% of self-identified Republicans said Trump was their preferred candidate, compared to 22% who picked Florida Governor Ron DeSantis.

In early May, Trump led DeSantis 49% to 19%, but that was before DeSantis formally entered the race.

The rest of the Republican field, which includes former Vice President Mike Pence who declared his candidacy last week, had single-digit levels of support.

Trump flew to Miami on Monday to face federal charges of unlawfully keeping U.S. national-security documents and lying to officials who tried to recover them. He has proclaimed his innocence and vowed to continue his campaign to regain the presidency in the election in November 2024.

He is the first former or current president to face criminal charges, but legal experts say that does not prevent him from running for president - or taking office even if he is found guilty.

Republican officials, including many rivals for the party's nomination, have said the charges against Trump smack of hypocrisy, citing classified documents found in President Joe Biden's Delaware home.

It is unclear if Biden, a Democrat, will face legal action. Biden's approval rating stood at 41% last week, close to the lowest level of his presidency. Trump had a 40% approval rating at this point in his 2017-2021 presidency.

In the Reuters/Ipsos poll, just 20% of Republicans thought Biden and Trump were both being treated fairly, compared to 77% of Democrats.

The poll included responses from 1,005 adults nationwide and had a credibility interval, a measure of precision, of four percentage points for all voting-age Americans and between six and seven percentage points for Republicans.

(Reporting by Jason Lange; Editing by Andy Sullivan and Howard Goller)