The attorney, William Taylor, says he and his client are being demonized because of the 2014 election.
House speaker once against criticizes Obama administration for failing to fully disclose information about concerns at the IRS, VA and elsewhere.
House votes to hold the former IRS official in contempt after she refused to share details of her involvement in agency's targeting of conservative groups.
The IRS scandal continues
House Speaker John A. Boehner (R-Ohio) said former IRS official Lois Lerner should testify before a congressional panel or be held in contempt of Congress.
The new guidance would amend current regulations governing which groups qualify as “social welfare” organizations.
Proposal by GOP lawmaker is in response to recent court rulings and the IRS scandal.
McConnell said the the IRS's targeting of conservative groups is symptomatic of a larger problem in the administration.
A new CNN/Opinion Research poll shows 47 percent of Americans think the White House ordered the targeting, up from 37 percent last month.
Americans for Fair Taxation, a group headed by wealthy super PAC donor Leo Linbeck III, will launch the ads Monday.