WASHINGTON – Florida election supervisors should take advantage of help from the Department of Homeland Security to make systems more secure, Sens. Marco Rubio and Bill Nelson wrote in a letter Monday.

"County election boards should not be expected to stand alone against a hostile foreign government," the lawmakers said in recommending "a wide range of services" from DHS to strengthen security.

"We encourage you in the strongest terms to take advantage of those resources, and to let us know about your experience with DHS and FBI."

Rubio in particular has questioned the readiness of some supervisors, calling them "overconfident," but has also sat down with them recently.

Russian hackers attempted in 2016 to gain access to at least five Florida county election offices, but there's no evidence of a breach. It's widely assumed that foreign operators will try to meddle in the upcoming November elections.

Here is the letter from Rubio and Nelson:

Thank you for all your efforts to prepare your county for Florida's upcoming primary and general elections. This year is demanding greater awareness of cyber threats, technical expertise, and cooperation among all levels of government than perhaps any other year.
 
Russian government actors targeted our election infrastructure during the 2016 elections. The Senate Select Committee on Intelligence recently released a summary of its findings regarding the scanning and penetration of state systems in 2016, along with recommendations for addressing vulnerabilities. Those findings included that Russia was preparing to undermine confidence in our voting process and that, in a small number of cases, cyber actors affiliated with the Russian Government accessed voter registration databases. The Committee further reported that, because the Department of Homeland Security (DHS) depends on states and localities self-reporting suspicious activity, and that activity is often difficult to find, "it is possible that additional activity occurred and has not yet been uncovered."
 
County election boards should not be expected to stand alone against a hostile foreign government. The Committee recommended—and DHS now offers—a wide range of services to state and local officials that will support your efforts to make your systems secure. DHS will follow your lead and meet your needs with a tailored set of options. We encourage you in the strongest terms to take advantage of those resources, and to let us know about your experience with DHS and FBI.
 
Elections run by local officials are the bedrock of our democracy. Our decentralized system is a strength, but it also means the responsibility resides with each of us to be sure our locality is secure. We look forward to working with you, DHS, and FBI to ensure successful and secure elections this year.

Related: Rubio applauds idea of election security consultants but again warns of risks