“Agreeing to the treaty does more than trample Second Amendment rights. It also threatens to erode all liberties guaranteed to Americans in the Constitution by establishing the precedent that the UN has some level of authority to govern our lives.”

-- Letter from Texas Attorney General Greg Abbott to President Obama warning that he and other attorneys general will sue if a UN treaty restricting firearms is ratified.

President Obama will stop in Denver today to renew his call for gun control measures en route to the San Francisco area for a quartet of fundraisers in his bid to help Democrats retain control of the Senate and retake the House next year.

Democrats certainly need the money given their depleted coffers and the enormity of their electoral task, and the president is going to the right places to get it. He will visit “Billionaires Row” in San Francisco and the home of a billionaire investor who specializes in subsidized green energy projects. On Thursday, Obama will head down the peninsula to scoop up cash from tech moguls.

And he’s coming in talking about the right topic for his benefactors. It was at a San Francisco-area fundraiser in 2008 that Obama found himself defending, albeit condescendingly, small-town voters who “cling to their guns and religion” and dislike outsiders.

Back then, Obama was explaining to wealthy donors why he was doing so poorly in polls ahead of his party’s Pennsylvania presidential primary, saying that opponent Hillary Clinton was benefiting from the “bitter,” backwards attitudes of those victimized by big business and its moderate political allies in Washington. He was explaining that the holdouts should be pitied, not blamed.

As Obama arrives, he will not only be talking about his call for gun control measures, currently facing long odds in the Senate due to opposition from Clinton Democrats, but also just after his ambassador to the United Nations voted to approve an international treaty restricting the international trade of firearms.

Obama is expected to sign the treaty, which will send the matter to the Senate for ratification. But the Senate has already signaled its disapproval for the treaty in a preemptive vote on a non-binding measure rejecting the pact, with eight members of the Democratic caucus joining with the GOP in opposition.

Gun rights activists have long warned of the dangers of the treaty, saying that not only would it result in a firearms registry, but that it would cede U.S. sovereignty on the Second Amendment and submit American citizens to the UN’s jurisdiction.

Proponents of the treaty say that the measure will help stop the flow of arms to dictators and genocidal maniacs and that U.S. gun sales are not the target of the legislation.

There is no chance that the treaty could get the two-thirds Senate majority required for ratification. But as 2014 draws nearer, the vote itself could still prove consequential.

Senate Majority Leader Harry Reid is currently trying to find support for some measure that would expand or improve the current system of background checks for gun buyers. That is proving difficult as liberals and conservatives battle over the creation of a federal firearms registry sought by the left to track gun purchases.

With that dispute proving hard to solve, the only measures proposed in response to the December massacre in Newtown, Conn. currently looking likely to pass are school safety grants and tougher penalties for gun trafficking.

This might be the end of the story if not for the rise of a well-funded, aggressive campaign to pressure moderate Democrats to support gun control. No doubt some of the Democratic patrons Obama will be courting today and tomorrow are among the donors to the new gun control pressure groups.

Red state Democrats grow nervous not just about facing general election voters opposed to gun control but also because of damaging primary challenges in which the party’s liberal base, fueled by outside special-interest spending, could prove problematic, especially in states like Pennsylvania, Maine, New Hampshire, Virginia, Michigan, Wisconsin and Minnesota.

Democrats are now facing votes on Reid’s watered-down gun bill, including a slew of amendments on gun control and now, likely the controversial UN gun treaty. While Reid might have hoped to have the issue of guns off the table in the next few weeks, the treaty will complicate and extend the process.

As Obama tours the nation in support of gun control he continues to help anti-gun groups ramp up the pressure on members of his own party. It is pleasing to the donors who have for years been frustrated by the remaining social moderates in the Democratic Party.

However much Obama hauls out of California this week, though, is unlikely to compensate for the electoral agony now facing Democrats caught between a party purge of gun-rights supporters and those very same “bitter” voters who rejected Obama in 2008.

And Now, A Word From Charles

“So all of this stuff -- the delays, the regulation, the arbitrariness, the unfairness -- is a direct result of taking over a sixth of the American economy on a flier, on a system that nobody else has devised in the history of man.”



-- Charles Krauthammer on Special Report with Bret Baier.

Chris Stirewalt is digital politics editor for Fox News, and his POWER PLAY column appears Monday-Friday on FoxNews.com. Catch Chris Live online daily at 11:30amET at http:live.foxnews.com.