At a rally for GOP Missouri Senate candidate Josh Hawley, President Trump said that the Pittsburgh synagogue massacre suspect and the man accused of sending bombs in the mail to prominent Democratic figures managed to slow the political momentum of Republicans before the midterm elections.

"We did have two maniacs stop a momentum that was incredible, because for seven days nobody talked about the elections," he said at the rally Thursday. "It stopped a tremendous momentum." He added, "More importantly, we have to take care of our people, and we don't care about momentum when it comes to a disgrace like just happened to our country."

"But it did nevertheless stop a certain momentum, and now the momentum is picking up," Mr. Trump said.

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He also hit Democrats as "loco" and a party of "rigid ideology and total conformity" at the second in a marathon of rallies before Election Day. Mr. Trump is in Columbia, Missouri, campaigning for Hawley, who is locked in a tight race against incumbent Democratic Sen. Claire McCaskill.

Mr. Trump kicked things off by bringing up McCaskill's risky vote against Supeme Court Justice's Brett Kavanaugh's confirmation. Later in the rally, Mr. Trump pushed that McCaskill supported Hillary Clinton and said she didn't "know the people."

Mr. Trump won Missouri by 10 points in 2016, and McCaskill is one of the most vulnerable Democrats up for re-election this year. A September CBS News Battleground Tracker poll found Hawley and McCaskill tied, each with 45 percent support among likely voters. The CBS News Battleground Tracker currently rates the race as a "toss up."

Mr. Trump tried to tie McCaskill to the national Democratic leaders and national protests, saying the party "resist and demean anyone who criticizes their radical ideas."

"You can't have dinner -- you see what they're doing to our people?" Mr. Trump said. "You see what they're doing to the people who represent your thought?"

Mr. Trump criticized the Democrats on immigration, saying they "are doing everything in their power to delay, to stop" the wall from being built. "And we need it more than ever," he added.

Mr. Trump also pushed his proposal to end birthright citizenship, which is guaranteed by the 14th Amendment of the Constitution. Mr. Trump called birthright citizenship a "crazy, lunatic policy" and vowed to end it, although it's unclear if that's possible.

Hawley, the state's attorney general, has tied himself closely to Mr. Trump during the race, and promised that he would vote in line with the president's priorities. McCaskill has tried to keep the race about local issues, especially health care. McCaskill has accused Hawley of wanting to strip health coverage for pre-existing conditions, which he denies. Hawley and the state of Missouri are currently engaged in a lawsuit to overturn the Affordable Care Act, which protects coverage for pre-existing conditions.

Mr. Trump is making several appearances on the campaign trail before Tuesday, all in states which he won in 2016. The president has largely focused on illegal immigration in the days before the election, a topic which could motivate Mr. Trump's base to turn out and vote in the midterms even though he is not on the ballot.

CBS News / James Morris

In addition to his usual claims that Democrats support "open borders," the president has largely focused on a caravan of migrants en route to the United States from Central America, and which are several weeks away from arriving at the U.S.-Mexico border. Earlier on Thursday, Mr. Trump discussed illegal immigration at the White House.

At a rally in Florida Wednesday, he said that "we're getting prepared for the caravan. Folks, you don't have to worry about that." Most of the migrants are seeking asylum. Over 5,000 active-duty military troops have been sent to guard the border, and Mr. Trump reporters Wednesday that he may send up to 15,000 troops to the border, which is more than number currently deployed to Afghanistan.

This week, he has also threatened to end aid to some Central American countries, and in an interview that Axios aired Tuesday, he said he intends to end birthright citizenship by executive order.