Exxon Mobil CEO Rex W. Tillerson is meeting with senators to make his case for why he should become Trump’s secretary of state. REUTERS/Jessica Rinaldi/File Photo

A Capitol Hill tour does not appear to be winning Trump secretary of state nominee Rex Tillerson any new supporters – but it is convincing certain senators that when it comes to sanctions, he may not be as pro-Russia as he seems.

Top Senate Foreign Relations Committee Democrat Ben Cardin (D-Md.) said after meeting with Tillerson for over an hour on Wednesday that the businessman was “pretty forthcoming” on sanctions and “understands the importance of sanctions and recognizes that you need to have the ability to get results.” He was referring to U.S. sanctions implemented against Russia in 2014 over its annexation of the Crimea and Moscow’s support for separatists in the Ukraine.

Cardin has not indicated  his support for Tillerson’s nomination. But the observation from the Senate’s chief architect of comprehensive new Russia sanctions — which are expected to receive some backing from key Republican senators skeptical of Tillerson — is potentially significant as the Exxon CEO tries to convince lawmakers he is fit to act as the country’s top diplomat.

Tillerson’s close personal and business ties to Russia sparked an early backlash from senators, including a handful of key Republicans, who found alarming his acceptance of the Kremlin’s Order of Friendship award in 2013 and his recorded opposition to Ukraine-related Russia sanctions in 2014.

One of those Republicans, Sen. John McCain (R-Ariz.), met with Tillerson on Wednesday, but did not appear more favorably disposed to the businessman.

When asked if he would support Tillerson’s nomination, McCain told a gathering of reporters “sure – there’s also a realistic scenario that pigs fly.” An aide later said he was joking – but the joke is potentially a revealing one.

So too was Sen. Marco Rubio’s (R-Fla.) dodge of a question about whether he would at this point be able to support Tillerson’s nomination.

“We’re not voting right now,” Rubio told reporters, after noting that “sure, absolutely,” he still has concerns about Tillerson’s nomination.

In the days the transition team announced Tillerson as President-elect Donald Trump’s pick for top diplomat, Rubio noted his “serious concerns” with the Exxon CEO, and tweeted that “being a ‘friend of Vladimir’ is not an attribute I am hoping for from a #SecretaryOfState.”

Democrats have made Tillerson one of their top targets in their efforts to stymie the march of Trump’s nominees through their confirmation hearings and into the administration. Because they cannot filibuster Cabinet nominations, Tillerson needs the support of only 50 senators on the floor – but because Republicans have only 52 seats, a small handful of skeptics could easily deny him approval.

Democrats are focusing their crusade against the businessman in two areas: his finances and his unorthodox relationship with Russia. In both areas, their case against Tillerson is expected to be a proxy battle for similar complaints against Trump.

Like Trump, Tillerson has refused to provide Congress with his tax returns, promising only “tax return information” upon request, and has complex business interests from which he must disentangle himself to hold public office. On Wednesday, Tillerson struck a deal with Exxon for a retirement package worth $180 million, to kick in if he is confirmed as secretary of state.

On Russia, Democrats plan to argue that Tillerson is a Kremlin crony who would be in sync with Trump’s praise of Russian President Vladimir Putin. Trump’s frequently-expressed admiration for Putin has created a backlash within even his own party that is especially problematic as lawmakers investigate the intelligence community’s accusations that Russia pursued election-related hacking  to help get Trump elected, findings Trump has vehemently discredited.

Tillerson’s advocates on the Hill have been working to convince their colleagues that his views on Russia are actually far more nuanced than those of the president-elect.

Senate Foreign Relations Committee Chairman Bob Corker (R-Tenn.), who has said it would be “hugely problematic” if Tillerson were aiming to dismantle sanctions the U.S. slapped on Russia, has stepped out to defend Tillerson. He argued in an interview last month that Tillerson actually “has a standard view of Russia’s malicious activities,” that would come across during his confirmation hearing as “certainly different, if you will, than the pictures of him toasting Putin with champagne.”

Back in 2014, Tillerson “understood that Russia needed to be punished,” Corker recalled from previous conversations with the nominee, but said he objected to the across-the-board U.S. approach to restricting Russia’s energy, banking and defense sectors with no consideration given to companies like Exxon with active contracts to work in Russia. Exxon estimated that sanctions cost the company about $1 billion in lost revenue.

As Corker tells it, Tillerson pointed to the European sanctions on Russia, which grandfathered in existing contracts, as a model he could respect.

“He understood that Russia needed to be punished, but he also understood that the Europeans were doing their sanctions in such a manner that was going to benefit their energy companies over U.S. energy companies,” Corker recalled. “He was just making sure people understood that.”

Tillerson brought up those same concerns about the disparity with Europe over grandfathering clauses in his meeting with Cardin on Wednesday, according to the senator.

“He said that he fully understands why America proposed sanctions, he wanted to make sure it was fair,” Cardin said. “I did make my point, that America is always going to lead. We’re always going to be asking more from our European partners, because that’s where we are.”

Moving through the Capitol, Tillerson did not respond to a question about how his meetings with senators were going or acknowledge the reporter who asked it.