Romney's Millions Can't Buy A Knockout Blow

Mitt Romney has won six of the ten "Super Tuesday" contests in the US - but failed to open a decisive lead in the race for the Republican nomination.

He won Ohio's Republican presidential primary, narrowly defeating Rick Santorum in the most critical and hard-fought of the nationwide campaigns.

The pair had been neck-and-neck and at one stage during counting it looked as if Mr Santorum might cause an upset.

Mr Romney also won in Massachusetts - where he used to be governor - and in Virginia, Vermont and Idaho.

Mr Santorum was the victor in Oklahoma, Tennessee and North Dakota, while former House speaker Newt Gingrich comfortably topped the poll in his home state of Georgia.

"Thank you Georgia! It is gratifying to win my home state so decisively to launch our March Momentum," Mr Gingrich said in a message on his Twitter account.

The 68-year-old badly needed a result to stay in the race to be the Republicans' choice to run against President Barack Obama later this year.

Ron Paul , who had hoped to take Alaska, finished the 10-state contest without a single victory.

Super Tuesday is the busiest day in the Republican race for the White House, with 419 of the 1,144 delegates needed to win the nomination up for grabs.

Primaries have been held in Ohio, Georgia, Massachusetts, Vermont, Virginia, Oklahoma and Tennessee, and caucuses in Idaho, North Dakota and Alaska.

Mr Romney , who won the four previous contests, had characterised the race in Ohio as a "battle for the soul of America".

His narrow victory in a state that will be hotly contested in November's presidential election underlines his failure to win over many Republican voters.

Despite spending tens of millions on his campaign, he has failed to connect with conservatives and blue-collar workers.

In recent presidential campaigns, the Super Tuesday primaries and caucuses have often settled the Republican race.

But it is thought this year's could run until April or May - or possibly until the last designated contest on June 26.

During his campaigning, Mr Romney has sought to keep the focus on Mr Obama's handling of the US economy, drawing on his own extensive business experience - he reportedly built a \$200m-plus fortune as a private equity executive.

"Other people in this race have debated about the economy, they've read about the economy, they've talked about it in subcommittee meetings. But I've actually been in it," he said recently.

Mr Obama is hoping to grab some of the Super Tuesday spotlight for himself by scheduling a rare White House news conference.

He has seen his poll numbers rise amid signs the US economy may finally be moving towards a sustained recovery.

A new NBC-Wall Street Journal poll released on Monday suggested he would defeat all of the Republican candidates in hypothetical head-to-heads.

Kansas, Alabama, Mississippi and Hawaii hold their contests over the next 10 days.

In total, there are more than 30 contests still to be held.