Republican presidential front-runner Donald Trump hunted for votes in three states on Monday ahead of a crucial round of nominating contests, and dismissed outbreaks of violence at his campaign events as "a little disruption."Trump, who made appearances in North Carolina, Florida and Ohio before Tuesday's primaries, told supporters that they could help him win the nomination and force establishment Republicans who have labored to stop his outsider candidacy."This is a place that I want to win. This is the place. This is going to do it. Ohio is going to make America great again," Trump said in the Cincinnati suburb of Vienna, Ohio. The businessman also told supporters what he saw as the failures of the US-led coalition in Iraq and the fight against ISIS. He said the country is in worse shape than before Saddam Hussein was overthrown. "Saddam Hussein was not a good person. Who cares? I'll tell you what, he was great at killing terrorists. He would kill terrorists. Now Iraq is Harvard University for terrorists. You go to Iraq, you want to be a terrorist you go to Iraq. That's Harvard, that's what they do. They kill. We don't do. They develop terrorists all over the place now. It is far worse than it was before we started."Five states - Florida, Ohio, Illinois, North Carolina and Missouri - hold nominating contests on Tuesday for the Nov. 8 election to succeed Democratic President Barack Obama.Trump could seize control of the Republican race with a sweep and possibly knock out two of his rivals, Ohio Governor John Kasich and US Senator Marco Rubio of Florida. Opinion polls show him leading in all five states except Ohio, where he is in a tight race with Kasich.