AP
During a Saturday rally in Waterbury, Connecticut, Trump took aim at Cruz, who on Friday used a Trump senior aide's comments suggesting the candidate was "projecting an image" to argue that Trump was deceiving Republican primary voters.
Trump was talking about Cruz when one of his supporters in the audience appeared to shout out, "Rafael!," referring to Cruz's given name.
"Rafael," Trump repeated. "Rafael! Straight out of the hills of Canada!"
He went on to summarize a line of attack that pervaded on the campaign trail earlier this year, when Trump frequently questioned whether Cruz was eligible to run for president because of his Canadian birthplace. Most legal experts have dismissed Trump's questioning, and many say Cruz is eligible because he was born to a US-citizen mother.
But Trump argued that if Cruz were to win the Republican nomination, "the first thing" the Democratic Party would do is bring a lawsuit against Cruz's eligibility.
Cruz renounced his Canadian citizenship in 2013 and has previously dismissed Trump's attacks. At least five Cruz eligibility-related lawsuits in federal court have been tossed out, according to NBC News.
Trump's attacks Saturday came at the first of two stops in Connecticut, which is one of five states to vote Tuesday and where polls show Trump with more than a 20-point lead. Trump, coming off a landslide victory in this week's New York primary, is poised to have another successful week in the Northeast and mid-Atlantic primaries.