I spent 1970-72 in Washington, DC, working with members of Congress and their staffers, and have had frequent contacts with them since. The subject of constitutional compliance has often come up. When I challenge the constitutionality of some proposed legislation, I often get that "You are the first person to contact us with that point."
Sen. John Glenn (D-OH) once admitted he disregards and has broken his oath of office to uphold the Constitution.
On July 16, 1996, the Senate Committee on Governmental affairs held hearings considering a bill to require Congress to specify for each new law which section of the Constitution gives it authority to pass the law. Sen. Glenn spoke out strongly against this requirement stating, "Why, if we had to do that we could not pass most of the laws we enact around here." He stated that the Clean Water Act, Endangered Species Act, the Americans with Disabilities Act and others could never have been passed if Congress had to find authority for them in the Constitution. He declared, "Americans just want us to solve America's problems of health and safety--and not be concerned if they can be constitutionally justified."
This is typical of the attitudes of members of congress, who, although few of them have a deep understanding of the Constitution, disregard it because their constituents don't make constitutional compliance a leading issue on which they decide who to vote for.
They also have, on more than one occasion, expressed to me (but not for attribution) that Congress passes many provisions that they know are unconstitutional (some have estimated more than 2000 per year), but they rely on the fact that the federal courts, and especially the Supreme Court, don't have time to hear cases on more than a few of those. In other words, their strategy is to flood the legal system with so much unconstitutional legislation that most of it will never be successfully challenged in the courts. This problem is the reason why many members of the federal bench have been pushing back, trying to avoid encouraging people to take constitutional issues to court, and encouraging them to take them to Congress instead.
I have asked several members about this and one of them once said to me, "If I only voted for things that are constitutional I wouldn't be re-elected." Others have said the same thing in similar words. So most of them know that much of what they are doing is unconstitutional. When I point out that Rep. Ron Paul gets re-elected by about 70% even when he is opposed, they seem baffled at how that can happen. I reply that Paul's constituents are not refugees from a libertarian planet. They are typical of people in other congressional districts, and that while they might wish Rep. Paul would "bring home the bacon" to their district, and say so, they also respect his adherence to the Constitution and vote for him despite their pocketbooks.
What the voters lack are leaders with some stature, such as constitutional scholars, to raise the issue of constitutional compliance for much of the legislation before Congress. If the question is framed as a choice between constitutional compliance and their pocketbooks, they often will vote for the Constitution. But their election choices are seldom framed to them in that way.