Supreme Court nominee Merrick Garland. (Kevin Lamarque/Reuters)

The conservative legal group Judicial Crisis Network, which is helping lead the fight against President Obama’s Supreme Court nominee, Merrick Garland, will launch a $2 million television, radio and digital advertising campaign aimed at blocking Senate consideration of Garland.

The new round of ads brings the group’s total spending on the Supreme Court fight to $4 million. It is the latest in an onslaught of opposition from conservative interest groups that are throwing money and researchers at a effort to halt the nomination process and discredit Garland, chief judge of the U.S. Court of Appeals for the District of Columbia Circuit.

In an unusual move this week, one notable business group also voiced its opposition to Garland’s confirmation. The National Federation of Independent Business, which represents small privately owned U.S. businesses, came out against Garland in an op-ed in the Wall Street Journal. It is the first time the organization is weighing in on a Supreme Court nominee in its 73-year history.

“After studying his extensive record, [the NFIB] believes that Judge Garland would be a strong ally of the regulatory bureaucracy, big labor and trial lawyers,” wrote NFIB President Juanita Duggan. “On behalf of the hundreds of thousands of members we represent, the NFIB opposes Judge Garland’s confirmation.”

Duggan cited Garland’s decisions in cases involving environmental regulations and labor law.

The JCN ads are slated to run for three weeks starting Monday. They will air in six states, targeting senators of both parties: Kelly Ayotte (R-N.H.), Joe Manchin III (D-W.Va.), Heidi Heitkamp (D-N.D.), Charles E. Grassley (R-Iowa), Michael F. Bennet (D-Colo.) and Joe Donnelly (D-Ind.).

Ayotte and Bennet, along with Grassley, who is chairman of the Senate Judiciary Committee, are up for reelection in November. Grassley, along with other Republican leaders in the Senate, has vowed not to hold hearings or a vote on any Supreme Court nominee until the next president is elected.

The 30-second television ads, titled “Let the People Decide,” are similar to a previous round of ads the group put out shortly after the death of Justice Antonin Scalia in February. They urge voters to support Republican senators who have promised not to move forward on confirmation hearings and to pressure Democratic senators who are in favor of them to reconsider. The group will also roll out sponsored Facebook ads over the next two weeks, echoing similar sentiments.

Some of the new television ads are tailored for each state. In West Virginia and North Dakota, for example, they aim to paint Garland as a liberal who will hurt the states’ coal and energy industries, respectively.