Hillary Clinton also had to deal with protesters while stumping.

Donald Trump was interrupted numerous times on Thursday while stumping in Portland, Maine. 

A group of people were removed from the event, all holding pocket Constitutions, a nod to the now-iconic moment by the father of a fallen U.S. soldier who spoke during the Democratic National Convention, blasting Trump for his anti-immigration rhetoric. 

It appears at one point, one of the protesters had a whistle. The protesters were booed and called "traitors" as they were removed. 

Trump stopped and watched every time he was interrupted. The Republican presidential nominee did not say much concerning the protesters other than commenting on how safe his rallies are because of the heavy police presence. 

During one of the interruptions, Trump began shaking hands with supporters seated behind him. 

Hillary Clinton also had to deal with protesters on Thursday.

The Democratic presidential nominee was swarmed by Secret Service agents when animal rights protesters got too close to her while she was stumping in Nevada. 

Clinton responded to the commotion by saying, "And apparently these people are here to protest Trump, because Trump and his kids have killed a lot of animals."

Watch video from both rallies below.

Another protester just escorted out. Holding pocket constitutions. #mepolitics #WGME pic.twitter.com/4Nhyob3EiG

— Dan Lampariello (@DanWGME) August 4, 2016

Protesters standing silently with copies of the Constitution held high booed by @realDonaldTrump supporters: pic.twitter.com/9swBnvoBYn

— Jeremy Diamond (@JDiamond1) August 4, 2016

Secret service storms protesters at Clinton rally. pic.twitter.com/pUWz6xF5gV

— Chris Reed (@CDReed) August 4, 2016