Republican presidential rivals Ted Cruz and John Kasich -- one waging a no-holds-barred stop-Trump campaign, the other battling to remain relevant into the GOP convention -- tried to make the case Sunday night during a Fox News town hall that despite Donald Trump's impressive primary wins that have him at the doorstop of the Republican nomination, he still can't beat Hillary Clinton.

Kasich touted two recent polls that have him edging out Clinton in a November match up. He also said he was the candidate that would appeal to Democrats too because he “has a positive approach.”

“I haven’t gone to the bombast. I haven’t said we have the apocalypse around the corner,” he said. “I think we can bring people together and raise this country.”

 

Kasich also said he’s hearing from primary voters in states that have already voted that they are having second thoughts about supporting current Trump and want Kasich to be the party’s nominee instead.

Cruz, who also said he could beat Clinton in the general election, challenged Trump to a debate in Indiana ahead of its primaries, saying people “deserve a debate." 

Both candidates agreed that Americans have a right to know what’s in the 9/11 report, and say 28 pages of sealed documents- which some suspect show a Saudi connection to the Sept. 11 attacks – should be declassified. 

“Get it out there,” Kasich said.

President Obama recently said he would make a decision as early as June on whether to declassify the pages. 

Both the George W. Bush and Obama administrations have refused to unseal the documents, claiming it would jeopardize national security. Critics say the reluctance is a calculated move to hide Saudi Arabia’s involvement in the attacks that killed almost 3,000 people.

Both candidates made their comments at “America’s Town Hall 2016,” with Fox News anchors Bill Hemmer and Martha MacCallum.  

The town hall also featured Cruz as well as political panelists that previewed the five upcoming high-stakes primaries this week.

The two-hour event in Philadelphia Sunday night comes just two days before Pennsylvania’s primary where Trump is hoping to collect enough pledged delegates to lock up the GOP nomination and avoid a contested convention in July.

In addition to Pennsylvania, primary contests will also be held on Tuesday in Connecticut, Delaware, Maryland and Rhode Island. In all 502 delegates will be up for grabs in total – 118 for Republicans and 384 for Democrats.

In Pennsylvania, Republican primary rules leave 54 of its 71 Republican delegates “unbound” meaning they are up for grabs at the national convention in Cleveland.

Trump needs 1,237 delegates to clinch the nomination. He currently has 845 delegates. Cruz is in second with 559 and Kasich has 148.

The Republican Party’s delegate selection and convention procedures – which Trump has railed against in recent weeks even as he continues to rack up victories – also was a hot topic.

Mike Puppio, a delegate candidate for Pennsylvania’s 7th congressional district, said delegates like him are going to be “guided by the will of the people,” but noted that the system currently “is not representative of the people but needs to be.”

“Listen, we need to unite and beat Hillary Clinton,” he said. “That’s the key for Republicans.”

On the Democratic side, Hillary Clinton is looking for a sizeable win against challenger Vermont Sen. Bernie Sanders. Tuesday’s primary comes a week after voters in New York gave Clinton a double-digit win over Sanders.

Unlike the more complicated rules for the Republican primary in Pennsylvania, Democratic allocations are much more straightforward with the state’s 210 delegates awarded proportionally based on the popular vote.

According to the Fox News delegate tracker, Clinton has 1,941 delegates compared to Sanders’s 1,191. To win the Democratic nomination, a candidate needs 2,383 delegates.