House Republican leaders believe they will keep a majority in the chamber in November, and on Tuesday, they pegged their hopes on selling their tax overhaul to voters.

Americans have not yet latched on to the tax policy the way GOP lawmakers had hoped ahead of the critical midterm elections. Only 27 percent of Americans call the law passed in December a good idea, while 36 percent think it is a bad idea, according to an NBC News/Wall Street Journal poll released this week. In a January poll, 30 percent of those surveyed thought it was a good idea, while 38 percent said it was a bad idea.

However, top Republicans who spoke to CNBC's "Squawk Box" on Tuesday argued that the plan's popularity should improve by November. The GOP has billed the law as its signature achievement during the first year of Republican control of Capitol Hill and the White House. It chops tax rates for corporations and trims taxes on many, but not all, individuals.

House Majority Leader Kevin McCarthy, whom Rep. Paul Ryan has endorsed to succeed him as speaker, told CNBC he believes voters will begin to understand the benefits of the law by the midterm elections. He even mused about the possibility of moving tax filing day to November instead of April so it is fresh in voters' minds.