A media blitz by the White House and its allies has failed to crack Republican opposition to President Barack Obama’s Supreme Court nominee, and it is all but certain the seat will remain vacant until after U.S. elections in November.

Television ad spending to support the nominee, appeals court judge Merrick Garland, has plummeted in the last two weeks, an indication the dispute is losing traction with the public. While 14 Republican senators have met privately with Garland, just two support a public hearing on his nomination. The Senate majority leader, Kentucky Republican Mitch McConnell, remains adamant that the next president, not Obama, will fill the court vacancy created by the death of Justice Antonin Scalia in February.

Democrats and their allies “are going to continue their messaging and continue to extract their pound of flesh, but I don’t think anyone expects it to happen this year before the election,” said Jim Manley, a Democratic strategist and former aide to Senate Minority Leader Harry Reid of Nevada.

Obama’s nomination of Garland, a 63-year-old white judicial moderate, was never likely to fire up the Democratic base in the way a younger, more liberal or minority appointee might. The drama of the Republican presidential primary has also eclipsed the Supreme Court fight at a moment of relatively high potential public interest, as Garland was introduced to the nation in the weeks after his nomination.

Through April 14, groups backing Garland spent about $1.6 million on television ads, according to Kantar Media’s Campaign Media Analysis Group. Since then, the only buy came from Planned Parenthood, which ran $137,000 in ads April 19 to April 25 attacking Republican Sen. Kelly Ayotte of New Hampshire for her opposition to his nomination, according to CMAG.

Garland’s opponents have spent more than twice as much on television ads. The Judicial Crisis Network, a conservative interest group, spent about $4 million from Feb. 19 through April 10 in 18 markets, according to CMAG.

By comparison, groups for and against the Iran nuclear deal spent more than $50 million on broadcast TV and national cable ads between March and October of last year, according to CMAG.

Publicly, Democrats maintain that Republicans will break. New York Sen. Chuck Schumer, the presumptive successor to Reid as Democratic leader next year, said his party plans to keep up pressure for a confirmation vote and that he expects Republican leaders to surrender before the election.

“In key states across the country, Republican senators are feeling the heat for their obstruction that would let Donald Trump pick the next Supreme Court justice,” Schumer said in a statement. “Their stance is causing an erosion of public support, and it’s only a matter of time before they go to Republican leadership and urge them to reverse course on the Supreme Court and pull the caucus back from the electoral brink.”

Yet Republicans have already endured considerable pressure. One interest group, the environmental organization Defenders of Wildlife, counted 501 editorials in 278 local newspapers through April 13 that criticized Senate Republicans’ obstruction of the nomination. Prominent Republicans, including former attorney general Alberto Gonzales and Baylor University President Ken Starr, have joined the criticism.

Democrats will try to maintain attention on the fight through public events, which may include staging an unofficial confirmation hearing, according to a Democrat involved in the confirmation effort. The nominee himself isn’t likely to be among those testifying, the person said, reducing the hearing’s news value.

A key barometer of Republican obstruction is the handful of the party’s incumbent senators who face competitive re-elections. Only their most endangered member, Mark Kirk of Illinois, has broken with McConnell to support a hearing and vote for Garland. Sen. Susan Collins, a Maine Republican who frequently works with Democrats and doesn’t face re-election this year, also backs a hearing.

“For the moment it’s not something that is a voting issue,” said Jennifer Duffy, an analyst who follows Senate elections for the nonpartisan Cook Political Report.

No Republican senator has broken ranks with Republican leaders on the strategy since Feb. 22, nine days after Scalia’s death, when both Kirk and Collins announced their support for a hearing and confirmation vote. The only two Republicans since then to express support for a hearing or vote, Jerry Moran of Kansas and Lisa Murkowski of Alaska, quickly recanted following a backlash from conservatives.

For other Republicans, the risk of alienating core supporters and donors motivated by the Supreme Court fight trumps the damage done with more moderate voters for whom the dispute isn’t very important.

“It would take a lot for a senator facing re-election to disregard what his party leadership is telling him to do,” said Michael Gerhardt, a University of North Carolina law professor and special counsel to Senate Judiciary Committee Democrats on the last two Supreme Court nominations. “Especially in a close election, you need your base and that’s part of what the party leadership is counting on.”

Ayotte’s re-election is a case study. A poll on the race released last week provided fresh evidence that even overwhelming public disapproval of her position on Garland’s nomination hasn’t much affected her political fortunes.

While 60 percent of likely New Hampshire voters said Garland deserves a confirmation vote, Ayotte maintained a 43 percent to 42 percent lead over her likely Democratic opponent, Gov. Maggie Hassan, according to WMUR-TV’s Granite State Poll. The results are in line with a poll that has shown the race virtually deadlocked since May 2015.

Political independents in New Hampshire favor a confirmation vote for Garland by 55 percent to 37 percent, but still back Ayotte’s re-election by 57 percent to 21 percent, according the WMUR poll.

That’s not to say Ayotte is unscathed. After the Democratic Senate Majority PAC spent an estimated $800,000 on TV ads from March 9 through April 3 assailing her opposition to Garland, her favorability rating declined in the WMUR poll from 47 percent in February to 41 percent. Her race is considered a “toss up” by Duffy’s publication.

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(Mike Dorning reported from Washington. Tim Higgins reported from San Francisco.)

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