Last week, after the Iowa's Democratic presidential caucuses turned into a debacle, Sen. Marco Rubio (R-Fla.) raised a credible point. The Florida Republican made the case that while Iowa's mess was bad, it's not difficult to imagine a far scarier scenario in which there's a close American presidential election, and a foreign power tries to "tamper with preliminary reporting system in key counties." Rubio added that the scenario may even produce unreliable results.

Around the same time, the Senate Intelligence Committee produced its latest report on Russia's attack on our 2016 elections, emphasizing the fact that the United States was "not well-postured" to counter Moscow's interference.

It was against this backdrop that Senate Democrats tried once more to advance election-security measures pending in the chamber. This afternoon, the chamber's GOP majority, once again, balked. The Hill reported:

Senate Republicans blocked an effort by Democrats to unanimously pass three election security-related bills Tuesday, marking the latest attempt to clear legislation ahead of the November elections.Democrats tried to get consent to pass two bills that require campaigns to alert the FBI and Federal Election Commission (FEC) about foreign offers of assistance, as well as legislation to provide more election funding and ban voting machines from being connected to the internet.But Sen. Marsha Blackburn (R-Tenn.) opposed each of the requests.

As a procedural matter, Senate Dems sought "unanimous consent" to advance the measures, which meant the proposals could be blocked by a single member.

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In case anyone needs a refresher, let's circle back to our earlier coverage on this. It was just last summer when Rubio partnered with Sen. Chris Van Hollen (D-Md.) on an election-security proposal called the Defending Elections from Threats by Establishing Redlines (DETER Act). The idea was pretty straightforward: if U.S. intelligence agencies were to determine that Russia interfered in another federal election, new sanctions would kick in targeting Russia’s finance, defense and energy sectors.

The point, obviously, would be to create a disincentive, letting the Kremlin know in advance that Russia would face significant economic consequences if Moscow once again attacked our democratic institutions.

The bill picked up a bipartisan group of co-sponsors, and it seemed like the sort of proposal that might even have a chance in the Republican-led Senate. Those hopes were dashed in December when the GOP balked: Sen. Mike Crapo (R-Idaho) insisted the bipartisan legislation had been "designed" to be bad for Donald Trump, and must, therefore, be defeated.

The circumstances seemed familiar for a reason: the DETER Act wasn’t the only election-security measure to be rejected by Senate Republicans. The Democratic-led House last year passed the “Securing America’s Federal Elections Act” (SAFE Act), which would, among other things, require voting systems to use backup paper ballots, mandate tech safeguards, and provide resources to states to improve their election-security measures.

In October, however, when Sens. Mark Warner (D-Va.), Amy Klobuchar (D-Minn.), and Ron Wyden (D-Ore.) tried to pass a package of election-related measures – including a Senate companion to the SHIELD Act – Republicans objected.

Soon after, the House also passed the Stopping Harmful Interference in Elections for a Lasting Democracy (SHIELD) Act, which would, among other things, require candidates to notify law enforcement authorities in the event of a foreign power offering campaign assistance.

Senate Majority Leader Mitch McConnell (R-Ky.) -- who picked up the “Moscow Mitch” moniker after balking at other bills on election security -- said his GOP-led chamber would ignore this bill, too.

A third bill, called the Securing America’s Federal Elections (SAFE) Act passed the Democratic-led House in June, and it would require voting systems to use backup paper ballots and mandate tech safeguards. This was part of today's trio, which Republicans rejected,

It's not too late for Congress to act in advance of this year's elections, but given recent developments, it's hard to be optimistic.