By Louis Jacobson and Linda Qiu

Politicians turned out on the Sunday shows to declare—or stay silent—about their allegiances in the upcoming presidential race.

On Meet the Press, former California governor Arnold Schwarzenegger declined to endorse the Republican presumptive nominee, Donald Trump, saying he would disclose his position on the presidency at a later date. On CNN, Florida Sen. Marco Rubio said he would support Trump because he so strongly opposes Hillary Clinton. And on ABC’s This Week, California Sen. Dianne Feinstein said it was time for Bernie Sanders to consider ending his campaign for the Democratic nomination.

In an interview on Meet the Press, Sanders sounded as if had no intention of dropping out anytime soon. Sanders said he believes he still has a chance to win the Democratic nomination by winning the California primary against Clinton.

But whether he’s ahead or behind in pledged delegates when the primaries end, Sanders said he intends to make a case to superdelegates to support him.

Sanders argued on Meet the Press on Sunday that he’s a better nominee for November because he polls better than Clinton in head-to-head matchups against presumptive Republican nominee Donald Trump.

"Right now,” Sanders said, “in every major poll, national poll and statewide poll done in the last month, six weeks, we are defeating Trump, often by big numbers, and always at a larger margin than Secretary Clinton is."

Sanders is largely accurate, but it’s important to note he hasn’t faced the same scrutiny as a national candidate that Clinton has. His statement rates Mostly True.

Poll position

We looked at polls taken during the last six weeks that tested Trump’s support against both Clinton and Sanders.

Out of eight polls, Sanders beat Trump eight times, and Clinton beat Trump seven of eight times. But in each case, Sanders’s lead against Trump was larger.

For example, the most recent poll, the NBC News-Wall Street Journal poll, showed Clinton beating Trump by 3 points and Sanders beating Trump by 15 points. That means Sanders bested Clinton’s performance by 12 points. In other polls, Sanders’s lead on Clinton was less but never fell below a margin of 3 points.

Case closed? Not quite, say polling experts.

Clinton has been scrutinized and attacked as a public figure for a quarter century, but Sanders—even after running for president for a year—is a relatively new figure to voters nationally. It remains to be seen how open voters will be to supporting Sanders once Republicans start airing negative attacks, especially ones that note his identification as a democratic socialist. (According to polls, being a socialist is a less attractive quality for voters than being an atheist.)

“General election polls don’t mean much until the conventions are over and you get to late summer or early fall,” said Kerwin Swint, a political scientist at Kennesaw State University. “A lot of voters don’t look at Sanders as a legitimate threat. It’s almost like he’s an imaginary candidate.”

And it’s worth adding, as Meet the Press host Chuck Todd noted, that Clinton can be expected to poll better against Trump after she officially secures the nomination and many former Sanders supporters come to her side.

Carbon copies

Sanders also said he will continue to make the case that his positions are more in line with the Democratic base than Clinton’s.

“Our campaign is about defeating Secretary Clinton on the real issues,” he said. “I want to break up the Wall Street banks. She doesn’t. I want to raise the minimum wage to 15 bucks an hour. She wants $12 an hour. I voted against the war in Iraq. She voted for the war in Iraq. I believe we should ban fracking. She does not. I believe we should have a tax on carbon and deal aggressively with climate change. That is not her position. Those are some of the issues that I am campaigning on.”

Sanders is right about Clinton’s Iraq war vote and where she stands on breaking up the banks, a $15 minimum wage, and fracking. But is he also right about their differences on carbon tax and climate change? That claim rates Mostly True.

There’s no doubt that Sanders’s rhetoric on climate change and his plan to deal with it are aggressive and, unlike Clinton, he has advocated for a carbon tax. Clinton does, however, have a climate change plan. While some environmentalists have said it isn’t tough enough, others have given it positive reviews.

Both the Sanders and Clinton campaigns referred us to each candidate’s climate change plan. Sanders’s climate change plan is long and comprehensive. Beyond a tax on carbon, it includes an array of proposals such as banning certain drilling and mining practices; cutting tax subsidies for oil and gas companies; investing in clean energy, alternative fuels, and energy efficiency programs; and improving the national public transit system.

Clinton’s plan is shorter and, though it doesn’t include a tax on carbon, it contains similar provisions on renewables. Clinton’s plan includes cutting tax subsidies for oil and gas companies; investing in clean energy infrastructure; and a $60 billion local-state-federal clean energy partnership.

As in her plan, Clinton prefers to focus on renewables on the stump and has specifically touted her goals for more solar panel and clean electricity as “big” and “bold.”

Clinton has gotten her best reviews from the League of Conservation Voters, who endorsed Clinton last fall (to some controversy). The green group considers Clinton’s plan strong and aggressive and, more important, achievable, Tiernan Sittenfeld, its senior vice president of government affairs, told PunditFact.

“Hillary is focused on practical solutions,” Sittenfeld said, pointing out that there are many lawmakers in Congress who still deny climate change science. “So [a carbon tax] is pretty remote possibility.”

But some are skeptical of Clinton’s “boldness.” Pulitzer Prize-winning website InsideClimate News called Clinton’s plan ambitious but said it “falls short of bold.” The Washington Post’s editorial board said her ideas are “second best.” Environmental news magazine Grist summed up her plan as not bad but “not quite the climate hawkishness we need.”