The solution to protecting democracy has never been 'buy weapons'. The solution to protecting democracy has always been 'enforce the standards of proper behaviour relevant to the office upon the holders of the office'. Strictly speaking it's not even restricted to democracy, it's just as valid for any office not elected or even entire government systems where regular referendums (or elections if you want to put it that way) are not a thing.
Of course, the punishment for failing to uphold the standards of proper behaviour would depend upon the offense and the office in question, but for elected officials any attempt to interfere with the election in any manner that weakens the people's ability to vote according to the people's own desires should be looked at with great scrutiny at minimum and likewise at minimum should result in dismissal of the official in question. Doing so in a particularly egregious manner (like permitting or even inviting a foreign entity to interfere) would be grounds for dismissal and permanent disbarment from public office and possibly restriction or permanent loss of the right to vote at all as well.
Of course, the punishment for failing to uphold the standards of proper behaviour would depend upon the offense and the office in question, but for elected officials any attempt to interfere with the election in any manner that weakens the people's ability to vote according to the people's own desires should be looked at with great scrutiny at minimum and likewise at minimum should result in dismissal of the official in question. Doing so in a particularly egregious manner (like permitting or even inviting a foreign entity to interfere) would be grounds for dismissal and permanent disbarment from public office and possibly restriction or permanent loss of the right to vote at all as well.