Clintons step up campaign

"This is one of the most momentous decisions any Texan could make," Mrs Clinton told a training session for campaign volunteers in San Antonio this morning. "You are, in effect, hiring the next president of the United States."

Her rival Barack Obama's string of 11 victories since the February 5 "Super Tuesday" contests has raised questions about the viability of Mrs Clinton's candidacy.

Mrs Clinton was winging back and forth between Texas and Ohio ahead of Tuesday's voting. She opened her weekend by rallying backers at a training session in San Antonio aimed at preparing activists for the incredibly complex primary system, widely known as the "Texas two-step".

Two-thirds of the delegates at stake in Texas will be picked during a traditional primary. That is followed on Tuesday night by a round of caucuses in the state's 8,000 precincts where the other third will be allocated.

Polls have shown Texas to be a virtual dead heat and the outcome could hinge on which campaign does a better job of getting backers to the polls. Mrs Clinton has a lead, albeit a shrinking one, in Ohio and the same dynamic is in place.

Mrs Clinton was heading to Fort Worth and Dallas, before flying to Ohio tonight to kick off an "88 counties in 88 hours" bus marathon through that state, stretching into Monday morning. Big-name backers led by Bill Clinton were already rumbling across Ohio as part of that effort.

The New York senator will then return to Texas for a televised town hall meeting, and she has purchased airtime to broadcast it across the state. She plans to await results which could decide her political future in Ohio on Tuesday night.

Mr Obama planned to hold a campaign rally today in Providence, Rhode Island. The Illinois senator has announced he will spend Tuesday night in Texas. A win in Texas would allow Mr Obama to counter the Clinton campaign's argument that although he has won more states, she has carried the big states like California, New York and New Jersey.

Many strategists argue that Mrs Clinton must win the big tests on Tuesday to continue her candidacy. Her strategists have begun to dispute that thinking and carve out a scenario for continuing if results in Texas and Ohio are disappointing.

However, as recently as February 20, even Bill Clinton pinned his wife's hopes on Ohio, in the Midwest, and Texas, in the South.

"If she wins in Texas and Ohio, I think she'll be the nominee," the former president told a Beaumont, Texas, audience. "If you don't deliver for her, I don't think she can be."

Mrs Clinton, a second-term senator, is aiming to become the first woman president, casting herself as the candidate with the years of service needed to take command on her first day in the White House.

Mr Obama, a first-term senator who hopes to be the first black US president, is seeking to chip away at those arguments by suggesting he would have superior judgment.

A Fox News poll released yesterday showed Mr Obama moving into a narrow lead of 48% to Clinton's 45% in Texas.

The poll, conducted between February 26-28, showed Mr Obama with a large edge among white men, blacks and younger voters, while Mrs Clinton leads among women, Hispanics and the oldest voters.

The Fox survey however found Mrs Clinton holding on to her narrowing lead in Ohio with 46% to Obama's 38%.

Obama has 1,383 delegates to Clinton's 1,276. A total of 2,025 are needed to secure the Democratic nomination at the party's convention in late August.

Presumptive Republican nominee John McCain and even President George Bush have seized on Mr Obama's lack of experience, trying to portray him as a smooth talker who is naïve about international affairs.

The Republican race is considered settled in favour of McCain, a former Navy pilot and Vietnam prisoner of war.

He has a total of 1,014 of the 1,191 delegates needed to clinch the nomination at the Republican convention in September. Mike Huckabee trails with 257 delegates.