In the view of Georgetown University law professor Steven Goldblatt, "Justice Alito is a much more predictable conservative vote than Justice O'Connor would have been." Even Kennedy, the current swing vote, has become more predictably conservative. According to The Washington Post, when the Court split 5-4 along liberal-conservative lines this term, Kennedy sided with the liberal bloc six times and the conservative bloc 13 times, including on the three cases cited above.
When earlier presidents nominated justices, ideology was often just one consideration among many. President Reagan was fulfilling a pledge to appoint a woman when he named O'Connor in 1981. When the Senate rejected Robert Bork in 1987 after a bruising ideological fight, Reagan tapped a moderate conservative, Kennedy, to avoid another battle. In 1990, President George H.W. Bush picked Souter, whose views were largely unknown, because he, too, wanted to avoid a fight with a Democratic Senate.
According to Toobin, "Presidents didn't used to run for office making promises about the kind of justices they would appoint. But President George W. Bush did, and he has delivered on those promises by transforming the Court in a short period of time."
Was the Court an issue to voters? In 2004, a Newsweek poll asked Americans how important each of 11 issues would be in their vote for president. The results, in order of importance, were the economy, health care, education, Iraq, terrorism, Social Security, taxes, the deficit, foreign policy, the environment, and—at the very bottom of the list—the Supreme Court. Although the Court was not a major issue for most voters, it mattered a great deal to Bush's conservative base, which has been protesting "judicial activism" for decades.
In 2008, the Court could be an issue for more of the electorate. "The stakes in the next presidential election are actually huge because the only likely Court retirees are on the left," said Thomas Goldstein, a Supreme Court lawyer who writes for Scotusblog. "A Republican president could really swing the Supreme Court in a very conservative direction, or a Democratic president could hold the line against further movement to the right."
So, yes, the Supreme Court did follow the election returns during the Bush presidency. After all, arguably, the 2000 election returns followed the Supreme Court.