The committee is asking 12 Democrats — most of whom are up for reelection or running for Senate in 2014 — why they haven't made more noise about the IRS's admission it targeted conservative groups for additional scrutiny.

“Senate Democrats — who pressured the IRS to target conservative groups — have an obligation to defend the citizens and organizations that were bullied by their own federal government,” NRSC Communications Director Brad Dayspring said in a release.

Dick DurbinDick DurbinRepublicans seek to lower odds of a shutdown No. 2 Senate Democrat opposes Trump's Supreme Court pick The Hill’s Whip List: 32 Dems are against Trump’s Supreme Court nominee MORE is a United States Senator, and that requires action not just hollow press releases — but he continues to hide behind them" reads one release targeting Durbin (D-Ill.)

The Republican committee includes four questions it wants Democrats to answer, including whether the targeted lawmaker will return campaign contributions from the IRS union, whether they believe Obama should apologize to groups that were targeted and whether they'd like an independent counsel to investigate the misconduct.

There has not yet been a concerted push from Republicans in Congress to appoint a special counsel to investigate the issue but Senate Minority Leader Mitch McConnellMitch McConnellExorcise the repeal and replace demon The Hill's 12:30 Report Scarborough: Bannon trying to ‘help his falling standing’ in WH MORE (R-Ky.) has indicated he's open to the idea.

Similar releases target 11 other Democrats. They include Sens. Mark WarnerMark WarnerTop Senate Intel Dem: Nunes's meeting on WH grounds 'more than suspicious' Sunday shows preview: Aftermath of failed healthcare bill Devin Nunes has jeopardized the oversight role of Congress MORE (Va.), Mark BegichMark BegichPerez creates advisory team for DNC transition The future of the Arctic 2016’s battle for the Senate: A shifting map MORE (Alaska), Mary LandrieuMary LandrieuMedicaid rollback looms for GOP senators in 2020 Five unanswered questions after Trump's upset victory Pavlich: O’Keefe a true journalist MORE (La.), Mark PryorMark PryorMedicaid rollback looms for GOP senators in 2020 Cotton pitches anti-Democrat message to SC delegation Ex-Sen. Kay Hagan joins lobby firm MORE (Ark.), Kay HaganKay HaganLinking repatriation to job creation Former Sen. Kay Hagan in ICU after being rushed to hospital GOP senator floats retiring over gridlock MORE (N.C.), Jeanne Shaheen Jeanne ShaheenOvernight Finance: WH wants to slash billions | Border wall funding likely on hold | Wells Fargo to pay 0M over unauthorized accounts | Dems debate revamping consumer board Path to 60 narrows for Trump pick Overnight Finance: Trump stock slump | GOP looks to tax bill for lifeline | Trump repeals 'blacklisting rule' | Dem wants ethics probe into Treasury secretary MORE (N.H.), Al FrankenAl FrankenTax reform an important part of pro-consumer energy policy We need congressional debate on Yemen The case against Gorsuch: It’s all about precedent MORE (Minn.) and Mark UdallMark UdallGorsuch's critics, running out of arguments, falsely scream 'sexist' Election autopsy: Latinos favored Clinton more than exit polls showed Live coverage: Tillerson's hearing for State MORE (Colo.) and Dick Durbin (Ill.) are all heading into reelection; Chuck SchumerCharles SchumerHow Obama's White House weaponized media against Trump Interior secretary hints border wall could be on Mexican land McConnell: ObamaCare 'status quo' will stay in place moving forward MORE (N.Y.) will be up in 2016.

Also included in the attack are Reps. Gary Peters (Mich.) and Bruce BraleyBruce BraleyTen years later, House Dems reunite and look forward Trump: Ernst wanted 'more seasoning' before entertaining VP offer Criminal sentencing bill tests McConnell-Grassley relationship MORE (Iowa), who have both announced they'll seek seats coming open because of retirements.

Schumer, Shaheen, Udall and Franken joined three other Democratic senators on a letter urging the IRS to do more to prevent political spending from tax-exempt nonprofits.

Democrats have fired back by pointing out that Senate Minority Leader Mitch McConnell (R-Ky.) has previously called for tougher IRS scrutiny for groups on both the left and right.

"No rational human being including Mitch McConnell thinks that Karl Rove and the Koch Brothers are operating social welfare organizations that deserve tax exempt status," said Democratic Senatorial Campaign Committee spokesman Justin Barasky. 

"However, Democratic Senators have been outspoken in their condemnation of what took place at the IRS."

In a Wednesday email to The Hill, DSCC Deputy Executive Director Matt Canter suggested Republicans were "overreaching" by continuing to hammer Democrats who have already all already condemned the IRS's actions.

Canter also noted warnings from other Republicans for lawmakers to avoid overreacting in their focus on the series of scandals that has plagued the Obama Administration over the past two weeks. He compared the potential fallout for Republicans to the 1998 election cycle.

After winning majorities in both the House and the Senate in 1994 and moving to enact more conservative policies, Republicans lost seats in 1998.

"Republican foolishness like this has many objective analysts wondering if 2014 could look like a repeat of the 1998 midterms," he said.

"Compared to today's GOP, a more moderate breed of Republican came into power in 1994, stormed the Bastille with unpopular policies that led to electoral defeats in the presidential year. They returned recognizing that their policies were disastrous for them politically, and promised to focus on jamming a President."

--This post was updated at 12:38 p.m. to reflect further comment from the DSCC.