Ted Cruz: America would “plunge into an abyss” if Donald Trump is elected as president.

Republican presidential hopeful, Ted Cruz, has warned that America would “plunge into an abyss” if Donald Trump is elected as president.

He spoke after Mr. Trump suggested Mr. Cruz’s father was connected to the man that killed President John F. Kennedy, the BBC reports.

The New York tycoon is poised to deliver a crushing blow to Mr. Cruz as Indiana votes in the latest primary.

Mr. Cruz’s advisers had targeted Indiana as the senator’s best hope of halting Mr. Trump’s march to the nomination.

However, polls show Mr. Trump with a sizeable lead in the mid-western state.

Mr. Cruz attacked Mr. Trump on Tuesday, calling the billionaire businessman “totally amoral,” “a pathological liar” and “a serial philanderer.”

Responding, Mr. Trump said “Ted Cruz is a desperate candidate trying to save his failing campaign.

“It is no surprise he has resorted to his usual tactics of over-the-top rhetoric that nobody believes.”

Mr. Cruz and fellow candidate John Kasich are hoping to force a contested convention where party officials, not voters, choose the nominee.

If Mr. Trump wins Indiana, the New York businessman will likely reach the required 1,237 delegates to secure the nomination and avoid such a scenario.

Meanwhile, in the Democratic battle, polls show Hillary Clinton and Bernie Sanders locked in a tight race in Indiana.

However, a Sanders win in Indiana would do little to erase Mrs. Clinton’s commanding lead.

The Clinton campaign has shifted its focus to other states, opting not to actively campaign or spend money in Indiana.

Mr. Trump told supporters on Monday that he is eager turn his attention to the general election.