Trump set to take on Rubio and Cruz at Houston Republican debate Thursday

Donald Trump has won three of the first four contests in the Republican presidential nomination fight.
Donald Trump has won three of the first four contests in the Republican presidential nomination fight.PHOTO: REUTERS

HOUSTON (REUTERS) - Donald Trump takes centre stage at a debate in Houston on Thursday (Feb 25) as the favourite to win the Republican presidential nomination, with time running out on his remaining rivals to change a race rapidly tilting away from them.

Trump, 69, has won three of the first four contests in the nomination fight for the Nov 8 election to succeed Democratic President Barack Obama.

After easily defeating his rivals in Nevada on Tuesday (Feb 23), the New York billionaire businessman is in position for more victories on March 1, when a dozen states will vote on "Super Tuesday."

At a CNN-hosted debate at the University of Houston, Trump's rivals will have one of their last best chances to try to derail the blunt-spoken political outsider before the Super Tuesday contests.

Whether they can pull it off is an open question. On stage with Trump will be US Senator Marco Rubio of Florida, US Senator Ted Cruz of Texas, Ohio Governor John Kasich and retired neurosurgeon Ben Carson.

None have been able to slow Trump's momentum in previous debates.

"Trump is on cruise control," said Eric Fehrnstrom, a former senior adviser to 2012 Republican nominee Mitt Romney. He said Trump should ignore his opponents and focus on the key planks in his platform - a border wall to keep out illegal immigrants, a stronger military, defeating Islamic State in Iraq and Syria (ISIS) and fair trade.

"It's getting late in the game for everyone else. People who are expecting a sudden shift in the direction of the race are deluding themselves. Trump is Goliath, and we've seen enough of the other candidates to know there are no Davids in this field,"Fehrnstrom said.

Rubio, 44, has an added incentive to change the makeup of the race. He is scrambling to attract the financial donors who supported one-time establishment favorite Jeb Bush, who dropped out of the race after his disappointing finish in South Carolina on Saturday (Feb 20).

'BOMBSHELL?'

Bush, the son and brother of former presidents, held a conference call with his top donors on Wednesday (Feb 24). A donor on the call said Bush offered effusive thanks for their support but provided no direction on who they should now help.

Cruz, 45, enters the debate under pressure. He must do well in his home state of Texas on Super Tuesday. Recently, he has been accused by his rivals of using negative tactics, including one that led to the resignation of his spokesman, Rick Tyler.

Romney, who has yet to endorse a Republican candidate, offered a pathway for attacking Trump, telling Fox News on Wednesday (Feb 24) that Trump was bound to have a "bombshell" in his tax records. "The reason I think there is a bombshell in there is because every time he is asked about his taxes, he dodges and delays and says: 'Well we're working on it,'" Romney said.

He added that all the candidates should release their tax records.

Trump tweeted in response: "Mitt Romney, who totally blew an election that should have been won and whose tax returns made him look like a fool, is now playing tough guy."