Sen. Bernie Sanders (I-VT) is slated to appear with Graham Platner, a Democrat running to unseat Sen. Susan Collins (R-ME), at a rally in Portland, Maine, on Labor Day, as the progressive leader from Vermont steps up his efforts to boost left-wing candidates who have been outspoken in their criticism of Israel and its ongoing war in Gaza.

Platner, a first-time candidate and Marine veteran who launched his campaign last week, has accused Israel of committing genocide in Gaza and backed Sanders’ recent resolutions to block arms sales to Israel. Platner’s rhetoric has faced criticism from Collins, a moderate Republican seeking her sixth term.

Sanders, who announced the rally on Monday, has not officially endorsed Platner, a 40-year-old oyster farmer whose past social media activity indicates he is a longtime admirer of Vermont’s democratic socialist senator. 

The Portland event on Sept. 1, the next stop on Sanders’ nationwide “Fighting Oligarchy” tour, follows a rally in Michigan on Saturday at which the senator sought to boost Abdul El-Sayed, a staunch critic of Israel who is vying to replace retiring Sen. Gary Peters (D-MI) in a crowded primary next year. 

In remarks over the weekend, Sanders, an early backer of El-Sayed’s campaign for the Democratic nomination, highlighted his efforts to restrict U.S. military aid to Israel and spoke out against the humanitarian crisis in Gaza, claiming that Washington is “way out of touch with where the American people are” on what he called “clearly a moral issue.”

“We are paying for the starvation of children in Gaza,” Sanders said to the crowd gathered at the Miller Auditorium at Western Michigan University in Kalamazoo. 

El-Sayed, for his part, echoed those remarks, saying that party leadership “is still pulling its punch on the fact that we are subsidizing a genocide in Gaza.”

“Maybe we should be using our taxpayer dollars, I don’t know, to build schools for our kids, rather than sending blank checks to foreign militaries who drop bombs on other kids,” El-Sayed said in his speech last weekend.

El-Sayed, a former health director in Michigan, is facing progressive state Sen. Mallory McMorrow and Rep. Haley Stevens (D-MI), a leading pro-Israel voice in the House who is favored by party leaders.