To win them over, he suggested, Republicans should emphasize issues that resonated with them at a time of insecurity, including government spending, debt, government bailouts and terrorism.
But he also presented some of his arguments in a new way to emphasize issues that polls show are important to voters as opinion surveys show the race tightening.
In these, the Republicans emphasized issues that had been secondary concerns in the previous Bush administration, including missile defense and North Korea.
Hickenlooper emphasized issues that weren't predictably polarizing, spending his energy, for instance, on his battle against homelessness, which he made sure to wage not just with government money but also with privately raised funds, including coins dropped in symbolic parking meters around the city.
The Iraq war is deeply unpopular with Democratic voters in Iowa and New Hampshire, and taxes are a bête noire for many voters in New Hampshire, which has no state income tax, so Mrs. Clinton is emphasizing issues that will resonate in those two states.
Amy Walter, national editor of the Cook Political Report, said that while Clinton may currently be emphasizing issues that resonate with Democratic primary voters, there was no reason to think the words were not honestly come by, and the candidate did not seem to be straying outside her central political identity.
The Republican electorate in Iowa is dominated by conservative evangelicals, whose influence in G.O.P. politics has waned nationally but grown in Iowa, which means that the state has a warping effect on G.O.P. Presidential candidates: it forces them to spend a year emphasizing issues that appeal to a hundred thousand religious conservatives who represent 0.03 per cent of the American population.
Both presidential campaigns are taking care to avoid that trap, emphasizing issues like education, health care and housing as much as, if not more than, immigration and related border issues.
Another key problem is that many of the so-called standard textbooks for this subject emphasize research issues that were important more than thirty years ago.
Analysts have learned to emphasize economic issues that resonate with Trump and to employ eye-catching graphics.
Mr. McConnell left his lunch with Mr. Trump and members of the caucus to emphasize the issues that bind congressional Republicans to Mr. Trump and play down the divisions underscored by Mr. Flake and Mr. Corker.
