Washington: Republican hopeful Mitt Romney had a commanding win in the Illinois presidential primary, taking him step closer to bag the party's nomination to challenge incumbent Barack Obama in the November presidential elections.

With about one-fifth of the votes counted, Romney, the former Governor of Massachusetts, had garnered 54 percent of the total votes polled, with his nearest rival Rick Santorum, the former Senator from Pennsylvania, trailing behind at 29 percent.

A win in Illinois – Obama's home State -- was considered a must for Romney to bag Republican presidential nomination this summer.

However even after this big win, American media said that the deal is not done yet for Romney.

"Mitt Romney got a much-needed victory in Illinois on Tuesday night, but his triumph is unlikely to change the dynamics of the GOP presidential primary," The Hill said, adding that Santorum is favoured to win the next contestants.

The Republican presidential campaign now moves to the Southern American State of Louisiana, which is headed by the Indian American Governor, Bobby Jindal.

According to a latest poll, Santorum lead Romney by 13 points in this State.

"Mitt Romney won Tuesday's Republican presidential primary in Illinois, a victory that widened his lead over his chief rival for the nomination and will likely provide a jolt of energy to his campaign.

Despite the victory for Romney, the race is unlikely to dramatically shake up the basic geometry of the race.

"Though Illinois is a major prize for Romney, who will claim the majority of the state's 54 delegates, the victory does not close the door on Rick Santorum, who will also win a portion of those delegates and has vowed to soldier on," a daily said.

It's the first time since 1988 that a Republican Presidential primary has been relevant in Illinois, the Chicago Tribune said.

The other two candidates, Newt Gingrich and Ron Paul, had polled less than 10 per cent of the total votes.

Gingrich, now placed a distant third and is unlikely to win the primary, accused Romney of using money power to bulldoze his opponents.

"To defeat Barack Obama, Republicans can't nominate a candidate who relies on outspending his opponents 7-1. Instead, we need a nominee who offers powerful solutions that hold the president accountable for his failures," Gingrich said in a statement.

"Over the past few weeks, my USD 2.50 gas plan has shown how America could have cheaper gas, more jobs and greater national security while putting the White House on the defence over their anti-American energy policies.

"This is the type of leadership I can offer as the nominee, and this campaign will spend between now and when the delegates vote in Tampa relentlessly taking the fight to
President Obama to make this case," Gingrich added.