President Bush's campaign strategy called for a flurry of vetoes to sharpen the difference between him and the Democratic Congress. But the approach may give the President political heartburn. He has pledged to veto a bill -- passed by crushing margins in both the House and Senate -- allowing local regulation of cable-tv rates. That sets up a nasty choice. If Bush puts up only token resistance, he could tarnish his Presidential aura by losing his first-ever override fight. But a serious effort to sustain the veto would require expending a lot of political capital to support cable operators in a showdown with consumer groups. The President will likely prevail on two other vetoes he signed on Sept. 22, but here, too, victory has a price. Democrats will blast the inconsistency of the GOP's "family values" campaign and White House opposition to a bill mandating unpaid family leave. And Bush is open to charges that he nixed a bill easing voter-registration rules on partisan grounds. The GOP fears the new registrants would be mainly Democrats.