A group pushing for the impeachment of President Donald Trump is launching a $3.1 million ad campaign targeting Republican senators over the coming weeks as pro-impeachment activists turn their fire away from Democratic holdouts toward members of the president’s own party.

The group, Need to Impeach, is funded mainly by billionaire Democratic presidential candidate Tom Steyer. Top executives said Tuesday that it will spend more than half of the overall campaign total on television ads, with the rest underwriting digital ads.

Targeted by the campaign are GOP Sens. Cory Gardner of Colorado, Susan Collins of Maine, Joni Ernst of Iowa and Martha McSally of Arizona, all of whom are seeking reelection next year and could cast votes in the coming months on whether Trump should be removed from office.

“With all that our country stands for, how can we have a president who thinks the law doesn’t apply to him?” a voice-over says in a sample ad provided to The Washington Post ahead of a scheduled Thursday debut. “Who would bargain away the security of our nation and our elections for his own political gain? We are patriots who have always protected democracy. Will our senator?”

Nathaly Arriola, executive director of Need to Impeach, said in an interview that the pivot toward Republicans represents a new phase in the group’s two-year effort to push for Trump’s impeachment. Before Tuesday, the group’s efforts – concentrated on grass-roots organizing and online advertising – were focused on persuading Democrats to launch the impeachment process.

That changed on Sept. 24, when House Speaker Nancy Pelosi, D-Calif., formally backed an impeachment investigation and all but a few House Democrats joined her in support.

The Need to Impeach campaign is the first major television ad spending supporting impeachment since the launch of the formal probe. The group spent nearly $12 million in the first half of 2019, according to federal disclosure records provided by the Center for Responsive Politics.

The Republican National Committee and the Trump campaign announced a combined $10 million in combined television and digital spending last week, with the RNC unveiling an ad that battled the accusations against Trump by raising questions about former vice president Joe Biden’s dealings.

“When President Trump asks Ukraine to investigate corruption, the Democrats want to impeach him, and their media lapdogs fall in line,” a voice-over says in that ad. “They lost the election, and now they want to steal this one. Don’t let them.”

Arriola said Need to Impeach plans to announce additional spending in the coming weeks targeting House Republicans who might join Democrats in voting to impeach Trump.

“However, we think it’s critical that Americans all over the country are actually seeing what’s happening in the Senate,” she said. “We can no longer watch as they quietly allow and enable this president to break the law.”

Kevin Mack, lead strategist for Need to Impeach, said some of the television ads would run on Fox News Channel and were designed to appeal to Republican and independent voters.

“We’re going to make sure that Republican voters in states with key Republican senators know what’s on the line here over the next couple months,” he said. “The tone of the ad is partly there to hold Donald Trump accountable but also to make it clear that these folks, these Senate Republicans took a constitutional oath just like the Democrats in the House.”

The ad spending comes as a coalition of activist groups announced a similar shift of strategy. This summer, groups such as Indivisible, MoveOn, Stand Up America, Women’s March and others joined forces under the moniker of “Impeachment August” to pressure House Democrats to come out in support of an impeachment inquiry. Now, they are branding their effort “Impeach Trump Now” and shifting focus to convincing Republicans as well as Democrats.

While dozens of Democrats did back an impeachment probe over the summer recess, it wasn’t until last month, with the emergence of allegations that Trump used U.S. military aid for Ukraine as leverage to secure dirt on Biden, that Pelosi and other senior Democrats embraced impeachment.

Sean Eldridge, founder and president of Stand Up America, said Tuesday that his group and partners would use similar tactics as seen in the Impeachment August campaign – pointing activists to lawmaker events, generating constituent phone calls to congressional offices and organizing a peer-to-peer text message campaign – to “put pressure on House Republicans to put country ahead of party.”

“It is heartening and it is significant that Democrats now have moved forward to support impeachment, but we can’t take our foot off the gas,” Eldridge said. “We have to continue to keep up the pressure.”