Hi Megan,

"je me suis sentie méprisée'" --> I felt scorned or despised or spurned.

I see méprisée as the past participle of the verb mépriser being used as an adjective that agrees with the subject "Je" (female.)     (The past participle is a verb form with several roles. It’s essential in the creation of compound verb tenses/moods and the passive voice, and it can also be used as an adjective. Ref. Lawless French)

The conjugation of sentir in the passé composé is correct as written above.

2) Not sure about this expression  --> vote blocking?

3) Blank vote  --  deliberately spoiled vote?

This is my best effort for you  -- hope it helps.

Let's see what the other contributors can add.

Bonne journée

Jim

"mon rejet de l'instrumentalisation du vote barrage" - my rejection of the instrumentalization of the blocking vote.

I know the term 'à faire barrage' has been thrown around a lot in the last few weeks, which is to vote against a candidate to block them, rather than for a candidate you like. My view of this phrase is she is trying to protest that she can be counted on to block a disfavorable candidate, which she says is not really a choice at all, rather than what she wants, which is that the system offers her a candidate that represents her values. She hates that it's becoming an instrument the system is using to "faire barrage." So she's going to "voter blanc" - not vote for either - rather than vote for a candidate just to block another.

Voter blanc -- to cast an empty ballot, i.e., not vote for any candidate.