Background: Benjamin Solomon Carson Sr. (born September 18, 1951) is an American neurosurgeon, author and politician serving as the 17th and current United States Secretary of Housing and Urban Development since 2017, under the Trump Administration. Prior to his cabinet position, he was a candidate for President of the United States in the Republican primaries in 2016. Born in Detroit, Michigan, and a graduate of Yale University and the University of Michigan Medical School, Carson has authored numerous books on his medical career and political stances.
Context: On March 11, 2016, a week after Carson ended his presidential campaign, he endorsed Trump, calling him part of "the voice of the people to be heard." Carson's subsequent comments that Americans would only have to sustain Trump for four years if he was not a good president drew criticism and he admitted that he would have preferred another candidate though thought Trump had the best chance of winning the general election. On the other hand, at the press conference Carson stated that Trump had a "cerebral" side.  On April 16, Carson spoke favorably of the possibility of abolishing the Electoral College, believing it disregards "the will of the people". Later that month, on April 25, Carson expressed opposition to Harriet Tubman replacing Andrew Jackson on the $20 bill, the day after dubbing the replacement "political expediency", though he indicated interest in Tubman having another tribute. In late April, Carson wrote to the Nevada Republican Party, requesting the two delegates he won in Nevada be released and free to support whoever they want.  On May 4, after Trump wrapped up the Republican nomination, he hinted that Carson would be among those who would vet his vice-presidential pick. The same day, Carson in an interview expressed interest in Ted Cruz serving as Attorney General of the United States, a position that Carson said would allow Cruz to prosecute Hillary Clinton, and then as a Supreme Court Justice nominee from the Trump administration. On May 6, Carson said in interview that Trump would consider a Democrat as his running mate, conflicting with Trump's asserting that he would not. A Carson spokesperson later said Carson expected Trump to select a Republican. Carson was said by aide Armstrong Williams in a May 10 interview to have withdrawn from the Trump campaign's vetting team, though the campaign confirmed he was still involved. Later that month, Carson revealed a list of potential vice-presidential candidates in an interview with the Washington Post. On May 16, Carson said the media could not keep opinion out of reporting and cited Walter Cronkite as a fair journalist that was in his words a "left-wing radical."  During the Republican National Convention, Carson appeared with former New York City Mayor Rudy Giuliani in support of the pro-Donald Trump Great America PAC at an event in Cleveland.
Question: what was the criticism?

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