US Election 2016: Marco Rubio emerges as candidate who can heal Republican divisions

Mr Rubio is now aiming his most consistent fire at Republican Presidential nominee Ted Cruz

Republican presidential candidate Senator Marco Rubio speaking in Iowa (Reuters)

Jon Williams, 55, a business studies teacher at a high school in a western suburb of Des Moines, was ready to go with Donald Trump for President – until the tycoon’s stunt last week, boycotting the final Iowa debate because he didn’t care for one of the moderators. Offended, Mr Williams has switched his allegiance.

Yet he is switching his support to Marco Rubio, rather than to the Republican who seems to have the better chance of stopping the Trump train – at least in Iowa – Senator Ted Cruz of Texas. “I just think Marco is the less divisive of the other two candidates,” he said at a Rubio rally at the weekend.

As Mr Rubio seeks to pull off a better-than-expected finish in the Iowa caucuses on 1 February, it is at Mr Cruz that he now aims his most consistent fire. Mr Rubio polled 15 per cent in the final Des Moines Register poll at the weekend, well behind both Cruz and Mr Trump on 23 per cent and 28 per cent respectively, but his aides whispered that their internal polling shows him doing far better.

“As people learn more about [Mr Cruz’s] record, they’ll realise that he really is very calculating,” Mr Rubio told CNN. “He’s always looking to take whatever position it takes to win votes or raise money – and we’re not going to beat Hillary Clinton with someone that will say or do anything to get elected.”

The increasingly bitter battle between Senators Cruz, 45, and Rubio, 44, both sons of Cuban immigrant fathers, has become a key plot-line of the contest in Iowa. The same poll showed that 20 per cent of Republicans who are not inclined to vote for Mr Rubio nonetheless have him as their second choice, higher than either of the other men.

Frequently funny and even charismatic on the stump, Mr Rubio has thus emerged as a signal problem for Mr Cruz, who has dedicated far more of his time and resources to campaigning in the state. If Mr Cruz fails to win Iowa or – his nightmare scenario – slips into third place behind Mr Rubio, his prospect of moving forward to the next states in the nominating marathon would be grievously damaged.

Mr Rubio, by contrast, is positioning himself to be the last man standing with a real chance to topple Trump over the longer term. He is attempting the neat straddling trick of winning over conservatives while at the same time appealing to moderates. It is that prospect that now has the party elders in Washington, who desperately fear a Trump nomination, pushing Mr Rubio as the anti-Trump candidate around whom they could coalesce.

Thus it was the in Urbandale suburb that Mr Rubio presented himself, over and again, as the healer that voters like Mr Williams are now looking for. “I will never divide you on purpose,” Mr Rubio, surely a reference to the sometimes bullying rhetoric of Trump. “At every opportunity, I will seek to unite us.” And, of course, defeat the person he expects to be the Democratic nominee, Hillary Clinton.