The Democrats’ congressional campaign arm pulled in $2.1 million in online donations over the weekend — the best four-day haul of the current election cycle — largely propelled by fundraising pitches tied to speculation that House Republicans could pursue the impeachment of President Obama.

Democrats have consistently used impeachment — a prospect that has been floated by several prominent conservatives but has not been embraced by most of the Republican establishment — to fill their campaign coffers, and their polling has shown that fear of an impeachment attempt as well as the House GOP’s efforts to sue Obama have the potential to drive midterm voter turnout on the left.

The Democratic Congressional Campaign Committee has brought in more than 114,000 donations since Thursday, when the House Rules Committee voted to go forward with a lawsuit contesting Obama’s use of executive action. Some Democrats have suggested that the lawsuit is a temporary stand-in for impeachment proceedings, and the online haul was spurred in part by nine e-mail fundraising pitches that directly mentioned the prospect of a GOP attempt to pursue impeachment.

“Grassroots Democrats across the country see Republican leaders in the House refusing to rule out impeaching the President even as they vote to use taxpayer funds to sue him,” DCCC Chairman Steve Israel told The Washington Post in a written statement Monday. “It’s no surprise that there’s outrage at this dramatic partisan overreach by an historically unpopular Republican Congress.”

The surge in donations came after White House senior adviser Dan Pfeiffer said at a Christian Science Monitor breakfast Friday that the Obama administration is taking the impeachment chatter seriously.

“Impeachment is a very serious thing that has been bandied about by the [2008] Republican vice presidential nominee and others in a very unserious way. We take it very seriously, and I don’t think it would be a good thing,” Pfeiffer said, referring to previous calls for Obama’s impeachment by former Alaska governor Sarah Palin.

Palin’s first impeachment call, published on Breitbart.com on July 8, resulted in $500,000 in DCCC fundraising in the 24 hours after it appeared.

The Republican establishment, however, has said consistently that it does not plan to pursue impeachment and instead has noted Democrats’ heavy use of it for fundraising.

“Our country faces real issues, including a sluggish economy, a humanitarian crisis at the border, and the unraveling of President Obama’s foreign policy around the world. But it seems Washington Democrats — including at least one senior White House official — would rather focus on phony issues and political games,” Michael Steel, a spokesman for House Speaker John A. Boehner (Ohio), said Monday.

Sen. John McCain (R-Ariz.), who vaulted Palin into the national spotlight when he chose her for the Republican presidential ticket in 2008, said this month that he disagrees with Palin’s calls for impeaching Obama.

“I respect always Sarah Palin’s views, but my particular view is that we should devote our energies to regaining the majority in the Senate,” McCain said in response to a reporter’s question. “I saw the impeachment scenario with former President Clinton, and it was not a good thing to do. The American people didn’t like it. The American people wanted us to do their work and that was overall opinion at the time. It did not sit well with the American people.”