With a budget showdown looming and a massive immigration overhaul waiting for a vote in the House, a handful of Republicans in the lower chamber are focusing on something more pressing: President Obama's birth certificate.

Though the president released his long-form birth certificate more than two years ago, the conspiracy theory that he was not born in America has, in some corners of the GOP, lingered.

At a town hall-style meeting over the weekend, Rep. Blake Farenthold (R-Texas) appeared to take the notion quite seriously when asked whether he would join some fellow House GOPers in pushing for a deeper dive into Obama's past. Indeed, he faulted the last Congress for failing to take on Obama over his birth certificate, and that as a result, "unfortunately the horse is already out of the barn on this, on the whole birth certificate issue."

When pressed on why Congress wouldn't just impeach the president and settle the issue once and for all, Farenthold suggested Republicans would do just that if it weren't for the Democratic-led Senate.

"If we were to impeach the president tomorrow, you could probably get the votes in the House of Representatives to do it," he said. "But it would go to the Senate and he wouldn’t be convicted."

Last week, Rep. Ted Yoho (R-Fla.) said he would put his weight behind a bill to investigate Obama's birth certificate should one come up in the House. Yoho said that though the birther issue was a "distraction," he had nonetheless called fellow Rep. Steve Stockman (R-Texas) — who said earlier this summer that he was still concerned about the legitimacy of Obama's presidency — to offer his support for such an investigation.

Other House Republicans have raised the specter of birtherism in recent weeks include Reps. Jeff Duncan (S.C.) and Markwayne Mullin (Okla.).

It's hard to envision a renewed focus on birtherism doing anything positive for the Republican Party.

For one, the belief is discredited and deeply unpopular. Nearly eight in ten Americans said Obama was born in the U.S. in a 2011 Washington Post-ABC News poll; only nine percent said there was "solid evidence" he wasn't.

That brings up the second problem with the persistent birther movement. Its most vocal proponents hail from the fringe of the GOP, and cast the party in the most unflattering light. Consider Donald Trump, who built a faux presidential campaign on birtherism, but ultimately didn't run because two-thirds of the nation despised him. Over the weekend, he once again suggested that Obama's birth certificate had been faked.

Here's Steve Benen at The Maddow Blog:

[L]et's not brush past the larger context here: just over the last couple of months, three members of Congress and a prominent national buffoon have all talked up a borderline-racist conspiracy theory that was discredited six years ago. It's one thing to lament the lack of progress in the national discourse, but for Republicans to still cling to birtherism, even now, is rather sickening. [MSNBC]

Even Sarah Palin recognized two years ago that the issue was a loser for the GOP, warning that it was "distracting" and "annoying."

Plus, if conservative diehards ever want to nominate Sen. Ted Cruz (R-Texas), whose star has been shining bright of late, as the Republican Party's presidential candidate, they may want to back off on the birther talk: Cruz was born in Canada. And that's the truth.