A majority of journalists are liberals. In this election, that will actually work against liberals.
First, it will be a problem because journalists can hardly seem to contain their fascination with the thought of Democrats regaining the House and perhaps the Senate. The problem with this? Reporting on this as though it were a done deal is going to alarm the conservative base that will plug its nose and pull the lever for Republicans. The result? Republicans will retain the Senate and, shockingly, come so close in the House that whether they "win" or "lose" will be academic for all purposes other than finger-pointing. That is, if the Democrats win by a single seat, say, they will be blamed for what happens even though they'll be largely ineffective to make anything happen.
Second, the fact that so many journalists are liberals has been a problem for liberal causes for years and will continue to be so in this election. If you've ever seen a math nerd dance, you intuitively sense the problem of people valiantly trying on activities that simply don't fit. Liberal journalists report what they don't understand and fail to properly analyze or review it. They accept nonsense from neo-conservatives and are afraid to label it as nonsense because they think that to do so would reflect a failing to provide unbiased news. To the math nerd, most dance moves look plausible, just as to the dancer most math problems look plausible. Liberal journalists are simply at a loss about how to report on conservative movements because they make little or no sense to them. Trying to be fair, they end up striving towards "fair and balanced" reporting of issues that are nonsense - issues like bombing people into liberation, banning the use of stem cells that would otherwise be disposed of, or insisting that kids who have grown up rich should not have to pay a tax on the income they've inherited by luck even while arguing that people who receive their income from working should pay taxes.