Within minutes of Mr Bush's announcement of his candidate - on television on Tuesday evening - pro-choice groups were complaining about Mr Roberts' conservative record, and his co-authorship of an argument submitted to the High Court in 1992.
It declared that Roe v Wade, the benchmark 1973 ruling that legalises a woman's right to an abortion, "was wrongly decided and should be overruled".
Karen Pearl, leader of the Planned Parenthood organisation, said her group had "grave concerns" that those might be Judge Roberts' views today.
The pro-choice Naral group staged a demonstration on the steps of the High Court yesterday and urged its members to bombard their state's senators with e-mails opposing the nomination. But, on Capitol Hill, where the decisive struggle will play out, Democrats were more cautious, aware of the broad admiration across the legal world for the skills of Judge Roberts.
Since 2003, he has sat on the appeals court for the District of Colombia - regarded as second only to the Supreme Court.
Robert Bennett, who represented former President Bill Clinton in several of his legal travails, described the nominee as "a superb choice", who deserved confirmation. Leading Senate Democrats for their part stopped short of threatening a filibuster against Judge Roberts to block his nomination. Harry Reid, the minority leader, admitted he had "suitable legal credentials," and vowed not to "prejudge this nomination".
But Dick Durbin of Illinois, the second-ranking Senate Democrat and a member of the Senate Judiciary Committee that must send Judge Roberts' name forward for approval by the full Senate, warned he was expecting "straight answers" from the 50-year-old nominee on abortion and other key issues.
"He has to be more forthcoming," Mr Durbin said, noting that, if confirmed, he could serve on the court for up to 30 years.
Yesterday, Mr Bush urged the Senate to set squabbling aside and provide a "fair and civil" confirmation process, so Judge Roberts could take his seat when the Supreme Court term opens on 3 October. Judiciary Committee hearings will start in late August or early September, Arlen Specter, the panel's chairman, indicated.
All in all, the reception given to the nominee has been less strident than might have been expected.Reuse content