Donald Trump on defence as he tries to regain momentum in Wisconsin

Following one of the worst weeks of his campaign, Republican presidential candidate Donald Trump was on defence as he kicked off a three-day sprint to Wisconsin’s primary. Contenders in both parties crisscrossed the Midwestern state seeking an edge ahead of Tuesday’s primaries, none more actively than Trump, who’s had a rough week and faces a likely struggle against Texas Senator Ted Cruz in the state, who has passed Trump in recent Wisconsin polls.

The Republican race is overshadowed by a persistent effort by Trump’s rivals in the campaign and the party to force the nomination fight into the July convention—and by his equivocations on whether he will be loyal to the Republican Party or bolt for an independent candidacy if he feels mistreated.

Trump began the afternoon with a rally in the Milwaukee suburb of Racine yesterday, where he defended a series of controversial comments in recent days on NATO, abortion and his remark that Japan and South Korea should perhaps be allowed to acquire nuclear weapons. (Also read. Donald Trump's controversial comment: 'Women should be punished for illegal abortions')

“This politics is a tough business,” said Donald Trump. “Because you can say things one way and the press will criticise you horribly. You say it another way and the press will criticise you horribly.” Off the stage, in a more reflective moment, Trump expressed regret that he had retweeted an unflattering photo of rival Ted Cruz’s wife, Heidi, paired with a glamorous photo of his own wife, Melania, a former model, as part of a bitter feud between the two men.

“Yeah, it was a mistake,” he told New York Times columnist Maureen Dowd. “If I had to do it again, I wouldn’t have sent it.” Cruz sought favour in North Dakota, which is not holding a primary or caucuses in the 2016 Republican race. He addressed Republicans at a state convention that is selecting delegates who will go to the national convention unbound to any of the presidential candidates.

Trump and Ohio Gov John Kasich sent supporters on their behalf to make the case that they should be backed by North Dakota’s delegates at the Cleveland convention in July. The Democratic race between Hillary Clinton and Bernie Sanders has grown increasingly bitter, too, though it has not matched the Republican contest for raw hostility. (Also read. Obama, Biden attack Donald Trump for 'exploiting fear')

Their attention will quickly turn to an even more consequential contest, in New York on April 19, where the Democratic front-runner dearly hopes to avoid an upset in the state she served as senator. Sanders, who was born in Brooklyn, can claim New York as his home state. Sanders urged rally-goers to come out in droves Tuesday.

“Here is the political reality,” he told a young and pumped-up crowd of thousands on the University of Wisconsin’s Eau Claire campus. “If there is a large voter turnout, if working people, many of whom have given up on the political process, if young people come, perhaps for the first time ...  we will win on Tuesday.”

Clinton sought to draw a contrast with Sanders by emphasising her Democratic bona fides. Before hundreds gathered in a hotel ballroom in Eau Claire later yesterday, the former secretary of state stressed that she has been “a proud Democrat all my adult life and I think that’s kind of important if we’re selecting somebody to be a Democratic nominee of the Democratic Party.” (Also read. Donald Trump slams Pakistan, calls the country a vital problem)