This article is more than 4 years old

This article is more than 4 years old

A new poll released on Saturday showed Ted Cruz taking a potentially decisive lead in the Republican field in Iowa.

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In a poll released on Saturday by Bloomberg and the Des Moines Register, the Texas senator had the support of 31% of likely Republican caucus-goers in the first-in-the-nation state, well ahead of Donald Trump at 21%.

The two were followed by retired neurosurgeon Ben Carson at 13% and Florida senator Marco Rubio at 10%. The only other candidate to poll above the 3% mark was former Florida governor Jeb Bush.

While the poll was only the second to show Cruz leading in the Hawkeye State, it was conducted by respected pollster Ann Selzer, who is considered the gold standard in measuring the attitudes of the Iowa electorate. Selzer has consistently outperformed her rivals in predicting the Iowa caucuses.

The poll showed a major collapse since October in support for Carson, who had reached 28%. His fortunes have fading as his foreign policy acumen has been called into question, in the wake of terrorist attacks in Paris and San Bernardino, California.

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In contrast, Cruz’s support has nearly trebled from 10% in October. Trump, who leads national polls of likely Republican voters, has shown only a marginal improvement, rising from 19% to 21%.

The result reinforces the conventional wisdom that Iowa is a two-man race between Cruz, who has a strong base among evangelicals, and Trump, who has built an organization to turn out the voters who have flocked to his populist campaign.

During a Friday appearance in Des Moines, Trump took aim at Cruz for the first time, criticising his opposition to ethanol subsidies – a popular issue in the agricultural state.