Complex sentence: By itself, this crystallized Jackson's opposition to re-chartering, which he vetoed when passed by the Congress, and caused him to view his eventual victory in the presidential election as a popular endorsement of his bank policy.
Split into simpler sentences: By itself, this crystallized Jackson's opposition to re-chartering, which he vetoed when passed by the Congress. This caused him to view his eventual victory in the presidential election as a popular endorsement of his bank policy.