Sen. Lindsey Graham (R-SC) this week took a step toward carrying on the legacy of his late best friend, Sen. John McCain (R-AZ), by putting his name behind a bill aimed at countering foreign election interference—the same one that McCain had sponsored before his death last August.

In doing so, Graham delighted his Democratic colleagues for picking up the Arizona senator’s example of bipartisanship in calling for a strong response to Russian election-meddling in 2016. He also seriously annoyed some in his own party’s conservative activist base, which views the bill as a disaster for free speech rights.

McCain, of course, often thumbed his nose at that very base and Graham has done so often, too. But unlike the original maverick, the South Carolina senator is a staunch defender of President Donald Trump. That, and his own reelection in 2020, are complicating Graham’s early attempts to keep the McCain spirit alive in the Senate.

The bill, titled the Honest Ads Act, was introduced in 2017 and proposes new disclosure rules for paid political ads on the internet, requiring those who place ads to reveal to the public who they are, how much they paid, who they were targeting with ads, and more.

It was officially re-introduced on May 9, and aims to ultimately prevent foreign entities from reprising the tactics Russia used in 2016—deploying fake anonymous accounts to blanket Facebook and other platforms with divisive and inflammatory ads—in order to influence political attitudes in the U.S.

McCain had been its lone Republican cosponsor in the Senate. Graham’s endorsement of the bill, announced by cosponsor Sen. Amy Klobuchar (D-MN) during last week’s hearing with Attorney General William Barr, gives the legislation the crucial seal of bipartisanship and breathes some life into the effort to pass it.

To many conservatives, the bill is a vehicle for a vast expansion of political speech regulation, not a novel new way to counter election interference. And they let Graham know it: on May 2, the president of the conservative advocacy group FreedomWorks sent a letter to Graham saying his group was “alarmed” that Klobuchar had named the South Carolina senator as a cosponsor of the bill.

In the letter, FreedomWorks’ Adam Brandon argued to Graham that the Honest Ads Act was too broad and would threaten the privacy of those engaging in political speech by requiring entities to publicly disclose their information when they buy an ad. He urged Graham to “reconsider” his sponsorship of the legislation.

FreedomWorks, which sent its letter to Graham the day after Klobuchar said he would cosponsor the bill, is the first and most prominent conservative group to target him, though other conservative groups have opposed the bill since it was introduced.

On Thursday, Graham told The Daily Beast he was aware of conservatives’ reservations with his support of the bill and said they had legitimate points. “We’re going to look at their concerns and try to accommodate them,” Graham said.

The goal of the legislation, Graham said, is to make sure that if you see an ad on Facebook or elsewhere, you can be sure it’s “not some Russian fake ad.”

“To the extent that it tries to redesign campaign finance law,” he said, “I do not support that.”

Graham has spent the last two years walking a fine line on the issue of Russian interference, balancing a possibly helpful image as a maverick in the McCain mold with his need to lock down GOP support in deep-red South Carolina ahead of 2020.

Since the release of Special Counsel Robert Mueller’s report on the investigation into Trump’s ties with Russia, Graham has enthusiastically amplified the president’s message that he was fully “exonerated” by Mueller’s findings. But he’s also made a point of warning that Russian meddling was serious and could happen again— a message the president has not exactly embraced.

In a statement announcing his support for the Honest Ads Act, Graham said that foreign election interference “poses a direct threat to our democracy” and that he’s backing the bill “because it’s clear we have to start somewhere.”

There is perennially chatter that Graham might be vulnerable to a primary challenge from his right. Conservative activists, particularly those in the libertarian-leaning groups like FreedomWorks, have never loved the South Carolinian, pointing to his votes in favor of liberal Supreme Court justices and his advocacy for a massive military budget.

But Graham’s stature on the right is far stronger these days, largely thanks to his outraged screed against Democrats during last year’s confirmation of Justice Brett Kavanaugh, which united nearly all on the right in admiration of the senator. FreedomWorks, which has been critical of Trump in the past, led its letter to Graham by mentioning his “work and passion” to confirm Kavanaugh.

That may have been part of Graham’s calculus. But conservatives said their reservoir of goodwill for him was not infinite.

“We need to see him coming back to the base more often, and supporting a bill like this doesn’t help him,” said Jason Pye. vice president of legislative affairs for FreedomWorks. “I’m not going to go out there and make threats and say that this puts his election in jeopardy, but it’s not exactly helpful in the grand scheme of things. It doesn’t make us want to go out there and help him.”

There is also Senate Majority Leader Mitch McConnell—who has long opposed most all campaign finance regulations—to reckon with. In 2017, when the Honest Ads Act was first introduced, McConnell said he was “skeptical of these disclosure-type proposals that are floating around, which strikes me would mostly penalize American citizens trying to use the internet and to advertise.”

Lee Goodman, a Republican former commissioner of the Federal Elections Commission, tied Graham’s stand to McCain in another way. “If you want to look back to some of the political problems that Sen. McCain had with the right, it had as much to do with his position on First Amendment rights and McCain-Feingold as any other policy position,” Goodman said, referencing McCain’s landmark 2002 campaign finance legislation with former Sen. Russ Feingold (D-WI).

Even though Graham said he is open to changes to the legislation, Goodman told The Daily Beast that the framework for it is totally broken.

“I can tell you this: grassroots conservative groups are going to be upset with Sen. Graham for forcing them to disclose who they are and where they are anytime they want to speak about an issue.”