Clinton's husband, former President Clinton, has asserted that his wife must win both Texas and Ohio to keep her campaign alive. On Friday, Hillary Clinton's advisers recast the stakes, saying if Obama lost any of the four presidential primaries - Rhode Island and Vermont also vote Tuesday - it would show Democrats are having second thoughts about him.
Hillary Clinton predicted success on Tuesday and looked ahead to the next big contest - Pennsylvania on April 22.
"I think I know what's happening and I believe I'm going to do very well tomorrow," she said. "I think that's going to be a very significant message to the country, and then we move on to Pennsylvania and the states coming up."
Clinton and Obama have been waging a tough and competitive race for the party's nomination, but Obama has seized the momentum, reeling off 11 straight wins in primaries and caucuses since Super Tuesday on Feb. 5. Superdelegates, the party's elected leaders and senior officials, also have been moving toward his candidacy.
As for Tuesday, Clinton said, "Obviously it's within the margin of error in both the popular vote and the delegate count. Ohio is the key to winning the presidency and I'm excited about tomorrow and I'm looking forward to it."
Speaking with reporters on her campaign plane, Clinton argued that the competitive primary contest would be good for the party heading into the November elections, a view at odds with some in the party who fear a lengthy, divisive nomination fight would weaken the Democratic candidate.
"Hard-fought primary contests are a part of American politics," Clinton said. "We're going to have a hard-fought contest, we're going to have a unified Democratic Party, we're going to get behind whoever our nominee is and we're going to win in November."
Lacking from Clinton's comments was the traditional confident assurance of victory.
"I intend to do as well as I can on Tuesday and we'll see what happens after that," she said.
With John McCain as the Republican nominee-in-waiting, Clinton said she's going to focus on national security because the former prisoner of war is certain to make that the core issue of the fall campaign.
"This is a wartime election, which Democrats haven't talked enough about in my opinion," said Clinton.
Later, in Austin, Texas, Clinton sought to underscore her argument that she's experienced on the issues by holding an hourlong town hall meeting where she answered questions on an array of issues from expanding health care to aiding veterans to boosting education. Her campaign bought time on a sports cable network to broadcast the event statewide.
Clinton strode the stage surrounded taking questions chosen from thousands that had been submitted, most on bedrock pocketbook issues. "We've got to have a new commitment to ending poverty," said Clinton, calling for a string of expanded anti-poverty programs. "All of that has to come together and I think it's way past time."
She was returning to Ohio on Tuesday to await election returns, but planned to head to Washington afterward.
Clinton opened the Texas portion of her swing with a noisy rally in an airport hanger in Beaumont for about 400 people, before heading to Austin. Clinton was sounding a populist theme and focusing on her support from retired military officers.
"Thirty retired generals and admirals have endorsed me, including two former chairmen of the Joint Chiefs of Staff," said Clinton. "They have endorsed me because they believe they will be well-served with me as commander in chief."
Clinton launched a new 30-second ad in Texas that criticizes Obama for failing to hold hearings as the chairman of the Senate Foreign Relations subcommittee on European Affairs, which has oversight for Afghanistan.
"Senator Obama, as chairman of an oversight committee charged with the force of fighting al-Qaida in Afghanistan, was too busy running for president to hold even one hearing," Clinton says in the ad that juxtaposes her experience on the Senate Armed Services Committee.
The ad includes a brief excerpt from last week's debate in which Obama acknowledges that he became chairman of the panel at the start of the campaign and hasn't held an oversight hearing on Afghanistan.
