A determined Hillary Clinton kept up a punishing campaign pace Thursday for the Democratic presidential nomination as the outlook for her bid to overtake front-runner Barack Obama appeared increasingly grim.
The former first lady aiming to become the first woman US president planned to travel thousands of miles to campaign in West Virginia, South Dakota, and Oregon, hitting three of the remaining six dates of the Democratic primary calendar in a single day.
"I am staying in this race until there is a nominee," Clinton vowed on Wednesday. "I am going to work as hard as I can to become that nominee."
But US media appeared to have decided Obama has virtually won the party prize. The New York Times wrote in a Thursday editorial that Clinton has "no plausible route to victory."
NBC anchor and analyst Tim Russert declared as the results came in early Wednesday: "we now know who the Democratic nominee is going to be and no one is going to dispute it."
A Los Angeles Times editorial concurred: "Clinton can't win: She has run a fine race, but she has lost."
Still, Clinton aides cast her narrow win in Indiana Tuesday as a sign of strength.
"We think the results last night strengthen the case that she will be the strongest candidate for the Democratic Party in November," strategist Geoff Garin was quoted as saying.
But some of the fire seemed to have seeped out of the New York senator, as she reeled off a toned-down version of her stump speech in Shepherdstown, West Virginia.
Significantly, she did not once mention or attack Obama.
Obama was reportedly headed for Washington for a fundraiser and meetings with uncommitted superdelegates, after a rare day off at home in Chicago.
The Illinois senator trounced Clinton in North Carolina's presidential primary Tuesday, bouncing back from weeks of missteps and controversy over his former pastor that had threatened to derail his bid to become the first black US president.
Clinton took Indiana by 51-49 percent, after her once commanding lead in the midwestern state dwindled to a mere 18,400 votes.
A top Clinton adviser acknowledged that even in a best-case scenario, Clinton cannot reach the 2,025 delegates needed to win the Democratic presidential nomination, The New York Times reported.
Counting delegates from discounted primaries in Florida and Michigan, Clinton would still be about 100 delegates shy of the finish line, campaign spokesman Phil Singer was quoted as saying.
Elsewhere, Clinton's failure to pull off a "game-changer" result in the twin primaries triggered calls for her to allow Obama to muster for a general election showdown with Republican John McCain.
George McGovern, the Democrats' defeated presidential candidate in 1972, urged the former first lady to step aside for the good of the party as he threw his support behind Obama.
And a prominent Clinton supporter, Senator Dianne Feinstein, said she wanted the former first lady to explain "her view on the rest of the race and what the strategy is."
Quoted in The Hill newspaper, which covers Congress, the California Democrat also said: "I think the race is reaching the point now where there are negative dividends from it, in terms of strife within the party.
"I think we need to prevent that as much as we can."
In a further sign she is floundering, Clinton lent her campaign 6.4 million dollars over the past month, according to aides. That took her personal input from her own fortune to more than 11 million dollars.
The Obama campaign subtly upped the pressure but seemed content to afford her a graceful exit.
Senator Claire McCaskill said: "It would be inappropriate and awkward and wrong for any of us to tell Senator Clinton when it is time for the race to be over."
With Obama only an estimated 177 delegates shy of the 2,025 needed for the party's nomination according to the independent web site RealClearPolitics.com, Clinton appears to be running out of options.
Analysts said the party's remaining undeclared superdelegates, party luminaries who can vote for the candidate of their choice, would start flocking to Obama's side in light of Tuesday's results.
At least four more superdelegates came off the fence Wednesday to endorse Obama.
"It will start as a trickle and end up as a flood in June," predicted Obama supporter Bill Daley, a commerce secretary under former president Bill Clinton.
