Updated

The Senate is expected on Monday to hold its confirmation vote on President Trump’s pick for CIA director, Kansas GOP Rep. Mike Pompeo. But the chamber’s Republican and Democratic leaders this weekend offered sharply different perspectives about the future of the president’s 20-plus Cabinet nominees.

Top Senate Democrats on Friday postponed Pompeo’s vote saying they wouldn’t rush through the confirmation process for Trump and fellow Republicans who control Congress.

Senate Minority Leader Chuck Schumer told CNN’s “State of the Union” on Sunday that several of Trump’s remaining nominees will be subject to “a thorough debate.”

The New York Democrat said he was “dubious” about eight or nine of Trump's picks -- citing potential conflicts of interests and policy stands.

The Senate has so far confirmed just two Trump nominees: Gens. James Mattis, as defense secretary, and John Kelly, as Homeland Security secretary, on Friday when Trump was sworn-in as president.

However, Senate Democrats have little chance of blocking a confirmation unless some chamber Republicans defect.

Senate Republicans have a 52-to-48 majority and need only a simple majority of 51 to confirm a nominee.

Senate Majority Leader Mitch McConnell expressed confidence Sunday about having enough votes to get all of Trump’s nominees confirmed.

“I believe we’ll be able to confirm the president’s entire Cabinet,” the Kentucky Republican told “Fox News Sunday.” “I’m optimistic.”

The prospects for former ExxonMobil CEO Rex Tillerson becoming secretary of state improved this weekend when two influential Republican senators expressed support, after having waivered over Tillerson’s past professional ties to Russia.

"Though we still have concerns about his past dealings with the Russian government and President Vladimir Putin, we believe that Mr. Tillerson can be an effective advocate for U.S. interests," Sens. John McCain, Arizona, and Lindsey Graham, South Carolina, said in a joint statement.

Tillerson also faces a vote Monday, before the Senate Foreign Relations Committee.

McCain, Graham and fellow GOP Sen. Marco Rubio, Florida, have questioned whether Tillerson has too many conflicts of interests to champion U.S. policy abroad, especially in Russia.

As CEO of ExxonMobil, Tillerson spoke out against U.S. sanctions levied on Moscow following its annexation of Ukraine's Crimean Peninsula in 2014. The penalties cost the energy giant hundreds of millions of dollars.

The episode became even more of a concern after the U.S. intelligence community concluded Russia meddled in the presidential election to help Trump defeat Democrat Hillary Clinton in the White House race.

McCain and Graham are not on the Foreign Relations committee, like Rubio. However all three will cast a final vote on the Tillerson nomination, if he gets enough votes Monday in the committee, which has 11 Republicans and 10 Democrats.

Graham told CBS' "Face the Nation" that he was persuaded to back Tillerson after they met privately.  According to Graham, Tillerson told him "when America doesn't lead, other people will, and the vacuum is always filled by bad actors. He said that we have to have a foreign policy that engages the world. We need to lead from the front."

McCain said on ABC's "This Week" that he talked to Tillerson about his views on Russia and his duty heading a major corporation.

“This wasn't an easy call," McCain said. "But I also believe that, when there's doubt, the president, the incoming president, gets the benefit of the doubt."

Rubio, who challenged Trump for the GOP nomination last year, clashed with Tillerson at a hearing earlier this month.

Rubio bristled at Tillerson's refusal to label Putin a "war criminal" or condemn human rights violations in Saudi Arabia and the Philippines in strong enough terms. He also chided Tillerson over the need for "moral clarity."

Hours after Trump was sworn in on Friday, Rubio was tight-lipped, saying he would make his decision "certainly before the vote" Monday and that Tillerson's responses to written questions had addressed "some of" his concerns.

Still, a "no" vote from Rubio would not doom Tillerson's confirmation, because the nomination could go directly to the Senate floor even without a positive committee recommendation. But it would be an embarrassing rebuke to Trump just as his presidency gets under way, with questions swirling about his ties to Russia.

The Associated Press contributed to this report.