The battle over U.S. President Barack Obama's latest Supreme Court nominee came into sharper focus Tuesday when Senator Mark Kirk became the first Republican to meet with Judge Merrick Garland, and the high court itself deadlocked on a major labor union case.
"I think we should do our job," Kirk said while sitting alongside Garland, whom the president tapped to fill the seat left vacant by the death of Justice Antonin Scalia last month.
"He [Garland] has been duly nominated by the elected president of the United States," Kirk added. "We need open-minded, rational people to make sure the process works."
In calling for hearings and a vote on the Garland nomination, Kirk is bucking Senate Majority Leader Mitch McConnell and other top Republicans who insist the next president pick the high court nominee.
Earlier in the day, the Supreme Court deadlocked 4-4 on whether public sector employees can be forced to pay union dues. That result means a pro-union decision by a lower court stands. It also illustrates the stakes in choosing Scalia's replacement.
Were he alive, Scalia, an arch-conservative, likely would have broken the tie with a vote striking down mandatory dues for California public school teachers.
U.S. Senator Mark Kirk, an Illinois Republican, meets with President Barack Obama's Supreme Court nominee Merrick Garland, at left, on Capitol Hill in Washington, March 29, 2016.
"Today's divided ruling from the Supreme Court establishes no national precedent," said Elizabeth Wydra of the Constitutional Accountability Center. "Such an outcome only emphasizes the importance of a court that can operate with a full complement of nine justices."
Arguments for and against
The Senate is in recess this week, but members are continuing a ferocious battle from their home states.
"Never before has a sitting president been denied his constitutional right to nominate someone for a Supreme Court vacancy," wrote Democratic Senator Tim Kaine in an op-ed for the Virginian Pilot newspaper. "Never before have members of the Senate advocated leaving the Supreme Court with only eight justices for nearly a year."
Republican Senator Orrin Hatch countered in an op-ed for the New York Times: "Considering a nominee in the midst of a toxic presidential election would be irresponsible. Conducting a thoughtful and substantive deliberation after the election is in the best interests of the Senate, the judiciary and the country."
So far, 16 Republican senators have indicated a willingness to meet with Garland. But the power to hold confirmation hearings resides with Judiciary Committee Chairman Chuck Grassley, and the power to call a floor vote resides with Majority Leader McConnell — both of whom have been dogged in their opposition to considering the nominee.
Control of Senate
"McConnell's biggest concern is making sure that he holds onto power in the Senate," said Republican strategist Ford O'Connell, who argues that Garland's fate could be determined by Republican perceptions of the presidential campaign.
"At this point, there is no chance of these guys [Senate Republicans] giving in," O'Connell said. "If [Donald] Trump or [Ted] Cruz or whoever has no chance [of winning in November], then you are much more likely to see McConnell try to make a deal."
"Republican control of the Senate pretty much lives and dies with the Republican presidential nominee's ability to win the White House," he added. "Many of these key Senate races are actually in presidential battleground states."
Watch: Judge Merrick Garland arriving on Capitol Hill.
Kirk is among a handful of Republican senators believed to face uphill re-election bids this year, representing states that often lean Democratic. Multiple polls have shown majority backing for Garland's consideration by the Senate.
Democrats would need a net gain of five seats to take control of the Senate next year.
Political analyst Norman Ornstein of the American Enterprise Institute says the basic math surrounding the Garland nomination has not changed.
"Grassley is still adamant there will be no hearing. McConnell backs him up. If either changed, the radical right media would go to Defcon I and treat them like piñatas," Ornstein said. "For McConnell, this is a no-win situation ... which leaves him unlikely to change."
WATCH: The Supreme Court is the highest court in the United States.